I start of washing as listed
http://forum.cliosport.net/display_topic_threads.asp?ForumID=6&TopicID=138293&PagePosition=1HERE
Then polish, seal and wax.
I have used the PC on my car once or twice since I have had it. Once to give it a really good polish to remove the swirls, then another time to try out some other products.
After you have removed all the swirls if you are sensible and carefull washing then you shouldnt have to remove them all again.
Some guys on here use the PC for every stage. I still tend to seal and wax by hand, so havent used my machine as much as others. On the other hand I have done a fair few cars for other people and friends so mine has payed fr itself.
As long as you dont start buffing dirty cars etc, the PC should be safe. Its not like a rotary where you can burn through the paint.
I was lucky to be able to trey before I brought with someones PC, may be worth seeing if anyone local has one to demo.