Great questions.
1. Yes, the game is planned to have a dom, sub and mid path. The midpath is where you progress through the story without reaching any TF stat threshold. At the moment, it's not very fleshed out, but it will serve as a path that typically allows you to pick whether you're taking a dominant or submissive path. The idea of having some sub/dom variation within the existing framework is something that is planned for the future. Like, even if you're sub, someone might be more submissive than you, and likewise for the dom path - always someone bigger and stronger out there.
2. Originally there were no picture selection options, until i got quite a few complaints about the MM stuff, so i added the ability to hide those pics. Your suggestion is correct though, it should all be selectable, but it will be quite a chore to go back and change everything. I'm using an old version of sugarcube, so there's a lot of things that need to be updated, and I'm waiting for the right time. So when I do go through the entire game, I can change a bunch of things all at once. Help finding pictures would be incredibly helpful, and there's a contribution section on my discord channel.
3. There are some parts where you can turn the tables on your situation - one of them is the coach path. You can expect to see more opportunities like that as the game progresses.