You will not burn the paint with your DA. You will be just fine.
Spread the polish on the paint work at around speed 3 or 4. Give it a good spread, then speed 3, work it in, several overlapping motions. Then when it starts to go clear, speed 4 until it goes nice and clear. It's quite hard to describe it, but I have now got the hang of it. Takes a while. Oh, and it still hurts the arms
But the finish is much more pleasing then doing it by hand.