A couple of things...
Sanding paint (putting scratches in) is easy.. Taking the scratches out is the hard and time consuming part.
Keep in mind that you are considering doing something that is aggressive (sanding) and requires something aggressive (compounding) to remove, all on paper thin (literally thinner than paper) clear coat, with very little experience.
Can it be done? Sure? Can you do it without screwing up? Maybe... But IF you do screw it up you are going to be in for either an expensive repair (which will never look as good/correct as factory) or a repaint (which will neverl ook as good/correct as factory).
A rotary will polish faster, but it is a double edged sword as there is far more risk for damage.
As far as stepping up the aggressiveness of your PC, take a look at this comparison.