So are the folks using Brightside cutting it with mineral spirits or the interlux product they recommend?

From reading the thread, it seems that they thinning and application of the paint is fairly easy to learn. It seems that it is the wet sanding and polishing that is the toughest thing to do right a pays the most benefits. My question is for a non painter how tough is this to learn? Is it simply following the prgression of finer grit paper each time and the same with the polishing. How hard is it to get a scratch free swirl free, glossy finish?

I don't want my $50 paint job to look like, well, a $50 paint. Job.