Jeb, removing the air pump will only reduce the front end weight a little and clean up the appearance of the engine compartment. Since you have no cats, there is no point in having an air pump. However, if you have to put your cats back on to pass smog inspection yearly, I would leave the pump in so that your cats work for the test. If not, go for it. Don't expect any horsepower gains.
You will also need to remove the pipe attached to the back of the heads which means that you will need to plug the holes with either 1" long 5/8" bolts or the real plugs.
A shorter belt will work for you, but you have to change the routing so that the belt doesn't hit itself. Here's a routing diagram:
