The idea is to allow you to use one item on another. I'm not going to change the UI at this point.
Glad you're enjoying it!
I think the scroll wheel up and down are reversed on the mouse since scroll up moves the items down and scroll down moves them up. Placing things with the mouse is easier for sure than the xbox controller but it's not impossible. I don't mind how it is since I don't play with the items that often anyways. Keep up the good work!