I've the suspect that you hardly polish your stuff becouse you've a pretty rough orange peel look: well compounds don't make miracles, they could help you but the better way is cut-out orange peel with a fine micromesh, than you could apply compound to achieve a mirror surface.
2- well it's really easy rub the pain off from edges: simply maks those with masking tape and after polishing works touch-up edges carefully.
3- at least if you rub -off some paint isn't a drama: simply touch-up with airbrush and a bit of decanting laquer, wait an other week (don't we all have a pile of models to start meanwhile last paint cures?
) and polish again (wash before)