It looks like you're going for a setup where each Stick can be whatever controller function in that spot, LS, RS, D-pad or ABXY, and then be able to change them around internally, which for button pressing can easily done in code. If AN value is <= 500 press A, if value is >= 524 press Y. That's of course not in any kind of actual code, but how it all begins. If that's what you're attempting it brings to mind the Radica Phoenix Revolution controller.
That all flies good for the D-pad and Sticks, but when it comes to ABXY it leaves some options lacking, as GoTeamScotch asked, like pressing X and B, or any kind of 3 button combination, it's also easier to mash a button repeatedly than flip a stick in some direction over and over.
It would give you 2 extra Stick 'click' buttons to be used for some things though. Interested in seeing how it works out, good luck with it.