Mazda Renesis Rotary Motor

Hey guys, my buddy bought an RX-8 last week and he let me take it for a cruise. WOW. At first I wasn’t SUPER impressed with it, although it is considerably more powerful than the Civic. But what I was impressed with is how it makes that power so well. I was not familiar with the rotary design hardly at all until he popped the hood and explained a few things. First off, the motor is tiny. With all the plastic garbage on top its hard to get a good estimate of its physical size (and it was dark out) but its much smaller than a traditional motor with similar HP output. I checked howstuffworks.com for a run down and some diagrams but still have some questions. Maybe someone here can shed some light. Why aren’t these kind of motors used everywhere? The only downside I can tell is less gas milage and oil consumption. Obviously there has to be more to it than that if its not used throughout the industry. Why is there 2 spark plugs per ‘cylinder’? Is this to keep the rotor spinning in the right direction or to combust the chamber more completely? (do they fire sequentially or together). How is the timing determined? As I understand it, the Renesis is a 2 rotor design… is more rotors better? More power? More complications? From what i read also, they are quite readily turbo’d, but what about super charging? Last question for now, but how is the direction the rotor goes determined? Does the starter turn it enough to keep its momentum going the right way? Seems to me as the combustion in the chamber went off, the rotor would to go the direction with least resistance, but obviously thats not a problem. Sorry for so many questions… I’m just trying to learn something.