As far as controller support goes, I would direct you to this thread and one of the more recent developer responses:
As someone who already uses a controller exclusively in this game it certainly needs some attention but, as stated above, it will (at some point) receive this. Even as it is I’m still able to clear all the content and pushed Arena to wave 242 (and could probably go higher though I lack the persistence to do so). However, I do still use the mouse for talking to merchants and organizing items while using the controller for combat. It’s been pretty fun thus far and I can only imagine it will become easier to use in due time.