There already is a “Go to XY Zero” button, or you looking for each axis individually.
As for go to home, without limit switches there is no way for the machine to know where that is. So the best you can do is pick a point, press the “Zero all Axes” button, then use the “Go to XY Zero”. Or do you want to have two buttons one to define “home” and another to “move to home”? Normally it’s done with limit switches, so that it’s a repeatable position after cycling power.
There are both freeware and ‘for purchase’ apps out there that will let you map a game controller to keyboard, see this thread
Give it a try. I’m still waiting on my table.