Only thing I could add is that yeah, after the 80 grit you should go to 120 as the next step.
I used to think I had to follow the formula all the way to red rouge, but every piece of metal is different. I finished a sportbike wheel last night and after starting with 80/120/240/320 the wet with 500, I hit it with emery and is looked great. No tripoli at all. I could have finished it off with white rouge but it's for a rider not a show bike. As some others have notide, the tripoli does seem to produce a haze sometimes. In future I will probably use it only to freshen up a previously -polished piece.
You _will_ find pits (bubbles) in any cast parts. Unless maybe theywere made for NASA...
Oh btw, the greaseless compunds can save you a lot of sanding.