Funny coincidence: I've actually employed the creator of Daughter of Essence to build some of the fancier-looking maps in TLS.
I've never worked much with open world games, and I can't promise anything with MMO-style mechanics. When it comes to class-switching, though, one of my upcoming projects might appeal. In Once Ever After, each character has one class unique to them, access to two or three major classes, and seven minor classes. Each class has different stats, but they also give "job points" used for skills, which you can then equip to any class. I think it has potential for the main game, but also lots of endgame optimization for players who want to fight the superbosses.
Regarding Patreon, you can put in any amount that you want, regardless of the tier you choose. If you want to support me that way, you could choose the $50 tier and input whatever you like.