Congrats...sounds like it's all coming together. As far as polishing goes, what your doing will work well. There are many different techniques to polishing. I use 3M's Perfect-it system along with their reversible foam pads. That's what works for me, Meguiar's makes excellent products as well, so what your doing is correct. You can finish sanding finer if you like but not needed.
As far as color sanding...your paint stopped flowing probably 15-20 minutes after you put it on, depending on reducer/hardner you used and how much paint you put on. I usually give paint 2 full days cure time before I start polishing, that's enough time for it to set up but not so long that it cat be cut by a good compound.
Runs...if a painter claims that they have never gotten a run, they haven't painted long enough.
Don't worry about the questions, just happy to help.