Thank you! Glad you're enjoying it. :)
There's been quite a lot of demand for fattening feeders, so that will definitely be included in my next update.
I want to make Dizzy's addiction more complex & also have it affect the player. That could work well with feeder girls running the shop instead of the player; they would unlock it as a date location, then try to persuade the player to eat there and become addicted to the doughnuts.
I've thought about your third idea a few times before, but you're right that it would be tricky to implement. May happen someday, though!