I have used an orbital polisher for several years. Orbital polishers by their nature will not harm paint if you follow the instructions and use common sense. I do not recommend the angle grinder style that the body shops use because they will usually leave fine swirl marks. The guys who do the clean up at most body shops are at the lower end of the experience scale. I have seen too many poor jobs with this type of equipment.
The paint on my Benz is original and as such is an enamel. This summer I used some fine white rubbing compund (Turtle Wax - Polishing Compound and Scratch Remover) to take out the marks that occur when washing. I always use a squirt bottle to wet the surface down and use the polisher to smooth out the paint. I also use a squirt of water to remove the haze. If you let it dry to long it is tough to remove. It takes time but the surface will be ultra smooth.
I follow it up with a hand applied wax, Simoniz Carnuba. Again, I use a squirt bottle to wet the paint to make things flow better.
I have used this technique for the past few years on my Audis and have also done work on various cars for friends. They always comment that my cars look like new.
It just takes a bit of know how, and a bit of time.
George
1965 230SL 4 spd - Papyrus white, Acquamarine leaher interior