I still haven't finished the game, but it looks really promising. However the english is horrible. I'm sorry, but sometimes I can't even make out, what's the text supposed to say. That's my only issue for now. Also it says "Ither" instead of "Aether" quite a lot. Anyway keep up the good work ;D
I really don't think so... the devs said they would mainly focus on Sarah. So I would expect some bug fixes, they will also add the gifting system (I think) and more scenes and story for Sarah. There is a small chance, but I don't want to give you false hope.
I think there is no code, you have to play the game and unlock it yourself. Also the text on the quests "wait for the next update", as in you need to wait until they update the game and add more content