The rotor in the center of the LiquidMotion device is shaped more like an oval (or race track) while the Wankel rotor is shaped like a bowed-out triangle. The LiquidMotion rotor has volume within that is carries gases, while the Wankel rotor is solid (or at least if it's hollow the volume inside isn't used). I don't recall ever seeing a counterweight on a Wankel but then I'm not even a little acquainted with Wankels in the field so it could be that Mazda forgot to tell me.
There is of course the possibility that this is a Wankel as far as patents would say. As different from a Wankel as a true Hemi is from a regular V8.
There's nothing inside-out about that design. They've just moved the location of the exhaust/intake porting. It's a neat reconfiguration idea, but it's still a Wankel engine.
Yep. Instead of the seals on the rotor, the seals are on the chamber (much better cooling and lubing opportunities). Instead of the intake/exhaust ports in the chamber, the intake/exhaust goes through the rotor (at first...)
The Mazda RX-8 uses a counterweight. (Actually, on the manual-transmission version it's a flywheel that has a sort of lip around the rim that's thicker on one side than the other.)
Aftermarket flywheels are generally symmetrical, with a way of bolting on a separate counterweight piece.
(The reason I know this is that I'm working on converting an RX-8 to electric. I got the car cheap with a messed-up engine, and I bought an aftermarket flywheel to replace the lopsided stock one because I don't want the car to shake itself to pieces. I haven't gotten around to ordering the adapter plate yet, but CanEV makes an RX7/8 transmission adapter plate along with two different versions of a coupler that attaches the motor to either a tapered-shaft style flywheel, which is what the car had originally, or a six-bolt variant for some other version of the engine.)
There is of course the possibility that this is a Wankel as far as patents would say. As different from a Wankel as a true Hemi is from a regular V8.