I'm sure the rotors rotate counter each other and that would counter each other out. As far as left/right balance I would imagine the vanes are computer controlled and the computer attempts to keep the thing balanced unless you move the bars to turn. Same as a Harrier or any other hovering type vehicle that makes forward motion and lift with the same rotor/jet.
Which is what this is, by the way. A two rotor helocopter. And the 10,000+ is because the ceiling is still theroetical as it hasn't been tested, but if you know the lift generated at max rotor speed, finding the mathmatical ceiling at a given temperature and barometeric pressure is trivial. Of course, over 10k feet you need oxygen to breathe. And you also need a IFR license, and all the IFR gear as you'll be under the control of a regional air controller, seeing as how you're flying in jet aircraft altitudes. Most ultralites list their ceiling this way for this reason.