only if it is loud, and it mostly causes slow acceleration
The AC condenser would effect the performance of the AC system in the car.
Putting a DVD player in your car will have a mild, but unsubstantial effect on your battery's voltage output.
yes
If it is dirty enough it will effect performance and fuel mileage.
The AIR is the Air Injection System. It doesn't effect performance being on your car, so I have no idea why you want to remove it. If it is an older car, the pump doesn't pull enough to hurt performance it just clutters up the engine comaprtment. It may not pass inspection if it is removed.
Anytime you make modifications to the a vehicle from how the manufacturer orginally made the car you have the possibility of damaging it.
You can gain extra performance for a 4 cylinder car in a variety of ways, it just depends on how much extra zip you seek, and how much you want to invest. Some ways to enhance performance are through replacing the car's computer module, installing a turbo kit, or putting in a cold air intake and after-market exhaust system.
NO
It can effect engine performance and fuel burning efficiency.
You have a system performance test done on your AC system.
Cooling System
sing like Micheal Jackson and Elvis and you