I've always polished with a sock (that sounds bad!). When you think you're done, polish some more. definately use their sealer. It can go on clear parts as well. You can also get different tones in color by priming individual panels, then "metalizing" before primer sets(when it's just dry to the touch)
this one has "primed" panels- leading edge, ailerons. Before I found sealer.
all I primed on this one is gunbay panels, panel under insignia, around exhausts, with sealer over all ancluding clear parts.
I have not tried masking after sealing, but have found you can use post-it notes without lifting any paint.