This is a big update, and some big plans! They sound very compelling though, so it should be worth it. I think it is fine to simplify the graphics especially if you are adding a lot of content.
I can totally relate with the feeling of wanting to add more to your first game, even if it was initially going to be smaller.
I ended up working on an infinite platformer gameboy item for shut-in angel, and haven't even gotten to the main things I wanted to add to the main game yet (I really should've made the minigame more simple).
EDIT: Got a win with a spiky healer! Didn't have the opportunity to convert both my units to spiky healers, but it was still very effective.