Homing is obviously a bit more tricky but is quite possible, the controller output goes to two drivers so it is possible to switch each driver input individually with a bit of logic.

As long as you do not overload the controller output I do not see a problem, if you end up taking a few more milliamps from the controller (within it's ratings) any electrical noise will be a less percentage of the signal and will apply equally to both drivers, so do not see why one axis would lose steps without the other.