Well, you could put the lateral CG way over to the right side, & it might hover level, but you'd still have lateral CG issues in cruise flight. Why bother?
I don't see how putting the tail rotor above or below the main rotor could reverse the thrust of the tail rotor. It's thrust that tries to move the helicopter laterally, regardless of the height of the center of thrust. Having the tail rotor above the main rotor is not uncommon.