are you allowed to use any controller since u can hook the USB attachment to it, cuz we were thinking of maybe using a steering wheel
As long as it doesnt require external power you can use it.
All of the supported devices are legal. The only exception to this is the wireless game pad.
Are we not allowed to use wireless controllers during competition? Is it because they require batteries to power themselves?
My guess is that it’s because of fear of radio interference. On the field, pretty much everything wireless is disallowed, with the exception of the actual robot radios.