Agree with a lot of this: exploring the ramifications and relationships, especially those the writers mightn’t consider. Sorry about the long post as I address some particular points and give my own thoughts.

So let’s assume April is back in her own body by the end of the first episode.

Oh goodness, I could already see the Big Finish cover for her episode now, with her in her human body at school but her eyes either red or smoking out black. Bringing Clara and Me in would be interesting, cause I could see some understandable resentment to the Doctor and his ilk for bringing them into this scary life. Though I could see BF being leery of doing crossovers too quickly, wanting the cast to stand on their own ground and not have main Who characters bail them out too much. Still, what you say brings in some interesting character dynamics. Though speaking of crossovers, ooh, what if Courtney Woods got involved in the mix? She traveled a bit with the Doctor but is she still going to Coal Hill and how does she cope with this alien stuff screwing around at home? How would she and the gang interact and rely on each other?

solve the problem via a trip to a galactic clinic. (Same with Quill’s pregnancy coming to a non-lethal-for-Quill conclusion.)

Funny you should mention Quill’s pregnancy. When announcing he wouldn’t do a Class series 2, Patrick Ness gave a tidbit of what it’d have been in a now deleted tweet (Link: https://blogtorwho.com/class-patrick-ness-announces-will-not-write-class/): “(weeping angel civil war & PLANET, Quill has a dangerous son, Charlie & Matteusz shirtless wood chopping…” Beginning with the son bit, having a son antagonist sounded interesting. I’d might involve Ballon’s daughter into the mix, see what click and clash might happen when she encounters her father’s killer and her supposedly dangerous half-brother.

Basically: I want a break-up. A temporary one, I hasten to addd, I’m all for them getting together again eventually.

Yeah, that sounds the good way to go for conflict. Maybe that “shirtless wood chopping” would come after they get back together again. ;)

I’m hoping that since the impact of the Angels is extremely visual in nature, Big Finish wouldn’t want to use them

Well…Big Finish had already did two or three well-reviewed audios where the Weeping Angels played a part. I listened to them and they did a good job. It mostly involved the sound of their movement and the characters vocally reacting to them. But I do agree with not using them too much in a hypothetical BF series. Ness’s tweet would give too much about them away and ruin their mystique (though “Weeping Angel civil war” gives me the amusing image of statues duking it out in the middle of the city and passersby being bewildered on why some were snarling and flipping the bird at each other).

Maybe have them at most have a background influence on the Governors and their goals before flouncing off when everyone gets what they want, leaving the Governors to go in and do their evil thing. That way, they could leave with dignity and mystery and not look like chumps since they’d be likely defeated. Speaking of that…maybe Dorothea Ames could be sneaked in back by having her having a backup plan in case she gets Outlived-Your-Usefulness’d and some hand-wavvy alien device brings back to life to do…things (Get back with the Governers? Be a third enemy? Take your pick). I agree with the last commentator, keep Cyril Nri as a sort of Big Bad.

For enemies, yeah some menaces of the week, maybe with them being themed around education, teenage, and teacher struggles in some way (Would students and teachers still be killed, was that ever an issue with the show’s perception? At worst, maybe the Governors could decide that this body count is just Too Much and is starting to get unwanted attention, so they do something with the rift or whatever so that whatever comes is least likely to leave behind a body count).