They fight against the residents of the evil Scarlet Danger Mansion and the puppetmistress, Alice, who hates men. Patchouli is now a mad scientist developing infernal machines for Remilia. Sakuya is now called Sally the Deadly Maid. Cirno is german and makes terrible puns about freezing things.
I'd think Sakuya would be renamed as Blossom instead, since Sakuya means Cherry Blossom after all. Most of the characters names would probably be Amercanized, like Yukari becoming Violet and Yuyuko getting some ghost pun name like 'Spectra'. The Gods would be renamed as 'spirits' and oni's as 'ogre's'. Utsuho's 'power of nuklear fusion' will be changed to 'power of the sun' and all caution signs will be replaced with sun symbols. Yumemi would lose her crosses and get x's or straight lines instead. Rumia doesn't eat humans anymore, only snack food or something like that. And
Sakuya Blossom will start to either get ridiculously poor aim at knife throwing, hit only clothing, or use magic bolts that only look like knifes but don't give you any wounds at all. Koakuma will be called an 'imp', not a demon, and Shinki and Byakuren would probably get cut out entirely.
And I'm nor sure if Letty's episodes are So Bad It's Good or genuinely good. If 4-Kids doesn't get his hands on it, I can imagine it to be a very fun and comical slife-of-life series with some magical elements. It might actually be fun watching.