Here are some stuff I would keep and change in SvtFoE if I did a rewrite/redo of it:
Change:
Make Star more of a likable,nicer,and more empathic main character by taking out the god complex/prideful ego,shortcomings, and selfishness,that would make her grow and truely learn from her mistakes and grow as a person instead of regressing and becoming more self-centered,egotistical,hypocritical,destructive,idiotic,vain,mean-spirited,ornery,irresponsible, and insensitive as the series went on. Have Star’s actions rewritten by showing how it could cause problems to others,have her not go way too far by being irresponsible and causing accidentsand continuing to run away from her problems by giving her morals and standards, and show stuff in front of Star to remind her of why she messes up and never takes responsibility for her actions and a justified reason on Star's flawsdue too not being taught humility as a child and getting her selfishness and ego due to her royal life and the amount of attention and being put on top of everyone she got from River and the guards,that way she can learn and mature from it. Also,I would expand the opening scene of the first episode to explain more on Star’s life and a backstory episode on how Star is the way she is.
Also,after Battle of Mewni, have Star become more mature,responsible,self-aware,open-minded instead of becoming more arrogant,short-tempered,ignorant,dumber, and still run away from her problems and containing to make mistakes and not have her go back to Mewni,but have her return to Earth, so she would humble a lot more and learn to be better given that she did more foolishness than learning in her Earth training and needs to prove to her family that she is responsible enough to handle herself and be a good ruler to Mewni. Have her attend therapy and train and learn under Marco and Glossryck’s spirit form and learning humility and responsibility,along with getting advice from her parents(Moon and River) and taught what a monster is. Also,explain how Star grew up without any real friends and have admit hated her old royal life,along with being told stories about the wars and conflicts of Mewni by her parents,that way that would make her more relatable and sympathic and less problematic and flawed to the viewers. Have her anger kept under tranquil fury and have her get mad or angry to a much lesser extent(similar to Wander,Mabel,and Phineas) than usual and keep her as a nice and good friend to everyone with morals. Have her get jealous in a good way by being upset at Marco’s relationship with Jackie by having a eye twitch or keep up a fake smile and have her a punch a wall at times without everyone watching or shouting loud inside her head,but don’t make her act impulsive so much without thinking and hurt people out of anger,even her own friends.
Keep:
Keep Marco in his original pilot characterization since he is meant to be a cynical,moody kid who almost hates everyone,except for his friends(Alfonso,Fergunson,Jackie-Lynn,Janna,and Starfan13) and loves his family. He would contrast way better with Star’s happy-go-lucky,reckless attitude and even have more of a point against her actions more,even being jealous of her popularity at school,always being complaining about being dragged by Star into her interdimensional adventures(why do I always have to be dragged into your adventures,why do I always have to clean up your dumb messes),and even in the finale of S1,he calls her out on her flaws and actions with a huge Reason You Suck speech after he and Marco nearly getting killed in the last adventure due to Star caring more about a sandwich than their lives at stakes. Also,Marco would start off hating Star,but he grows closer to her and becomes a better person similar to Amity and Scratch.
Change:Don’t make Solaria horrible as a mom to Eclipsa and make her a ruthless mother-hating pyscho,make her the Odin of the story,by having her help the Magic High Commission despite her old age and even after Eclipsa is recrystalized,she took her power and wand.
Keep:Moon as the way she is before,a overbearing queen and struggling mother who tries to be a good mom but fails at it and acts too controlling and cold towards Star. Also,keep her cool warrior queen side and not abandon it after the fight with Meteora and keep her overprotective side towards Star,but make it more reasonable. Keep her original Royal queen look from Seasons 1-2.
Change:
Don’t ruin Moon’s character with contradiction and character assassination in Season 3,then pull a 360 degree on her that ruined her character in the final few episodes of the series. Make her a perfectionist as a personality then realize her own flaws later on and change into a better parent after acting too controlling towards Star here.
Instead of Moon still acting overbearing towards Star and later,having her relationship with Star become more negative in the later season,have her show her as not as a cold and stoic queen by showing her to be pretty nice towards her own kind and other races like all monsters,but she has limits at trusting some of them. Also,I would have her midway through the series have her realize her perfectionist personality by becoming too controlling and cold to the point she realizes how much she gone too far by acting cold and controlling towards Star here.
I would have more reasons on why she was hardly a good and such a neglectful and cold mother to Star,given how I think in my rewrite of Battle of Mewni,Star would’ve told Marco that her mother never really cared about her and her father was always there for her due to her being too busy with duties or being away,but deep down Moon cares for Star and never really shows her love for her and hides it because she never learned humility early when being raised as a queen. Have her bond with Star grow stronger and closer as the series goes on,along with a justified reason why she acts so cold and rude towards her as a mother due to not learning humility and was pampered and spoiled as a queen that made her so invulnerable,being formally friends with a lizard which resulted in him killed off her mother, and it sends a reason on why she wanted to change the system by remembering she is queen,she would restore balance now. I also as a overprotective mom,I would have her not wanting star to get hurt till she finally learns maybe its good for her daughter too learn along and grow up to be a good wise ruler rather than continuesly being a cold-hearted control freak towards her.
Keep:
The books about the 22 queens of Mewni,but explain it to the audience and start off an arc similar to the lost 3 journals of Gravity Falls.
Change:
Have Moon’s relationship with Eclipsa not be conflicted or bigoted,by having Moon instead of being bigoted against her,She shows concern and horror for her and fears her infamous reputation would impact all of Mewni if she is broken out of her crystal prison. But later,feels sorry for her when she is in a coma and finds a source to her cure with Ambrosia’s help. Also,have her discover the truth about the secrets of Mewni instead of Star herself,realize her father,Lazlo Marmalade now a old man is still alive and out there in Mewni,and find out about the true cause of her mother’s death,since she died of Natural Causes instead of killed off by Toffee,meaning the Council lied anout her deathand go war,since a friend on Wiki Fandom revealed that this was a discarded idea from the series that never got used in Season 3-4.
Keep:
Butterfly Castle,but have it rebuilt after being destroyed by Meteora instead of being left in ruins.
Change:
Expand the first season from 13 to 20 episodes to give more room for character development,story/continuity,world-building,and lore. I would also make Battle of Mewni and the finale hour-long episodes.
Keep:
Toffee
Change:
Do not kill him off,but have his gooey remains revived by a cult of monsters and have him brought back with allies to get revenge on Star and Moon for the former for killing him before. Also,give him more depth by explaining a reason why he hated Mewmans was due to his family being killed by magic(the reason Seth wanted to destroy magic)and vowed vengeance against the Butterflies,have Moon bring his finger back to him after he succeeds in defeating and killing off Star and Marco(who come back after going to the spirit realm and Glossyrck sends them back with the power of love/friendship to fight Toffee)in Battle of Mewni,and show how and Moon used to be friends before Seth raised and molded him to be a ruthless conqueror like him(similar to King Andrias and Anakin Skywalker)and have Moon tell it to Star.
Keep:
Ludo and his villain/redemption arc.
Change:
I would have the narrative explain why he and the Avarius family hated the Butterfly family and why he wanted to steal Star’s wand so he can make his family proud and accept him again. Also,after his redemption,have him reunite with Star and Marco at the end and have Star and Ludo becoming friends now. Also,have him more of a sympathetic villian by showing as much as he attacks and kills people,he never goes too far in killing anyone compared to Toffee,have him hate his parents for being abusive and forcing him out of their kingdom,but loves his brother,Dennis and would do anything for him. He also shown to dissprove racism and hates being mocked and tortured by everyone. Also,he is not a fan of spoiled royalty,even despite being a hypocrite,he mocks Star for her irresponsibility and recklessness. Also,have him be protective of his pets and beats anyone who hurts them. He would also stand up to his parents for their abuse and mistreatment of him(similar to Pacifica and Amity).
Keep:
Mina Loveberry,but still keep her as a joke character while becoming more psychotic later on.
Change:
have her ally with the MHC since they used to serve Solaria in the wars of Mewni,have them team up in wiping all monsters from Mewni and have Rhombulous power her soldiers with crystal suits and be the one who uncrystalizes Globgor instead of Moon asking him to do it. Also,make her more pathetic than before by having her betrayed by Hekapoo,Omnimatrix Prime,and Rhombulous for using them and having her beat down by Star and Marco in a final battle,while requiring help from other solarians and have Star,Marco,Eclipsa,and Moon remove the powers for her soldiers,making them powerless and Mina being thrown in a mental asylum,while the MHC are forced to do community service to make up for their irrational deeds towards the Butterfly family.
Keep:
Eclipsa,her family,and arc.
Change:
explain more of Globgor’s backstory and how he regretted his past bad crimes agaisnt Mewni due to his love with Eclipsa and being softening over the years.
Keep:
The Blood Moon Ball.
Change:
Show and explain how the painting of Eclipsa’s dad said the mysterious words of Marco about the blood moon.
Keep:
Starco
Change:
Have Starco built up without any toxic nonsense or TomStar arcs and take out the Beach Day photo. Also,have Star apologizing to Marco for admitting his crush on him back at the party when her mother took her back to Mewni. Also,have Star and Marco grow closer to each other by going on dates before kissing and getting together and becoming king and queen of Mewni at the end.
Keep:
Meteora
Change:
Have Eclipsa,Moon,Star,and Marco all fight Meteora at once together instead of just Star herself. Also, I would not make Star give the wand back to Eclipsa and have her keep it and let her mother,Moon continue to be queen instead and remove Moon’s fight with Meteora that caused the whole Moon Amensia conflict instead.
Keep:
Have River use his scepter,but use it more than just one time.
Change:
Have Moon’s relationship with Eclipsa not be conflicted or bigoted,by having Moon instead of being bigoted against her,She shows concern and horror for her and fears her infamous reputation would impact all of Mewni if she is broken out of her crystal prison. But later,feels sorry for her when she is in a coma and finds a source to her cure with Ambrosia’s help. Also,have her discover the truth about the secrets of Mewni instead of Star herself,realize her father,Lazlo Marmalade now a old man is still alive and out there in Mewni,and find out about the true cause of her mother’s death,since she died of Natural Causes instead of killed off by Toffee,meaning the Council lied anout her deathand go war,since a friend on Wiki Fandom revealed that this was a discarded idea from the series that never got used in Season 3-4.