Swirls: trace, soft wax, vs microscratches
I disagree with prev posting, swirl marks are usually (in MHO) on top of the clearcoat and are as a result of wax thats still there and not completely buffed off or smoothed properly. If you can rub a finger accross a swirl mark, its in the wax or finish. If you can't ? its then in the clear-coat and is sometimes called micro-scratches or "spider-web" scratches. They show up especially in the reflection of a bright source of light like the sun.
I agree that one should use caution with a powered polisher/buffer, but the new random/orbitals are pretty safe. The old style ones that simply spin at a reasonably high speed are risky, not so with the Porter-Cable or DeWalt. Have a look at some of the other threads on use and look into the Detailing Guide on the autopia.com site too. There's a great detailed explanation on how to use R/O polishers.
Micro-scratches can be reduced by getting down to the clear-coat, using a great polish like Einzett, Zaino or Klasse's All in one, then put on a Sealant Glaze. I have a Jet-Black 330ci that shows microscopic traces of anything in the finish and got rid of them by doing these methods.
On washing? I will never let any machine wash brush touch the cars finish. Never go to a "community car-wash" and never let anyone else put a mitt on the car. One drop on the driveway... back into the bucket and then on your car and presto-cadabra... microscratches. A dirty car is better than a clean but scratched one. Get the kit from Wayne's towels, I need and use 2 waffle-weaves for drying and 3 Ultra-plush micro-fiber buffing towels for final prep.
Best of luck, look up the guide and you'll get a maintain a great finish.
Gary