I love that question, "Do you know how to work on rotaries?" It's the same as any other RWD car until you take apart the actual engine block. I don't know many people that take apart the engine of a two year old car. As for the time to improve the engine, the 8 is about as powerful as you can make an N/A 13B and have it pass current emissions standards. It is not that hard to make a balls-out 300hp N/A 13B, but it will never pass emissions. Similarly, it is very possible to make a 30mpg rotary but then it would be "underpowered" and "no fun."
Two is too many? :eh:
Running an RE car hard will result in about one quart per thousand miles. Keep in mind, Honda DOHC VTEC cars can do the same (S2k's and new Civic Si's love to drink oil.) Average consumption in my '7 is about 3/4 quart per thousand miles, my damn Mitsubishi chokes down more then that. It is good practice to check the oil level of any car at the gas station, every fill-up. That's usually printed in the owner's manual.