PLUS, the biggest thing, which everyone seems to ignore/forget is that you only have LIMITED clearcoat. ANYONE can probably remove swirls/scratches with a machine polisher, the skill is in using the least aggressive combination possible to remove the smallest amount. Also, if you haven't owned your car from new, you REALLY need a Paint Depth Gauge, otherwise you are effectively going in blind - it may have been machine polished to death previously, so you could 'burn through' very quickly.
As said above though, I'd skip DA, use some common sense and learn to get on with a Rotary, but don't skimp on machine or backing plate, and don't go in 'gung ho' and make holes in your paint, or skim the paint of the edges of your bodywork.