There are inspections every 12 months. But I believe they only do OBDII readings, so with a MIL cheater or a tune with a rear o2 delete you should be good. Do some research to find out for sure though.
you can always do 02 sensor cheater (extender) so the check engine light doesn't turn on. Just depends where you take it for inspections. Here in NJ they run the car under a camera and look for a cat regardless. If that's the case take to a gas station for emissions, Or get a hollow cat welded on they are about 40 bucks online
No I never did and plan on getting it tuned soon as I have some extra cash. At the same time I put the larger throttle body and the k&n filter on. I felt a little difference. I get about 30mpg on the highway doing 65.