Chopper -- I always wait for the paint to dry - this way you don't have a chance of a peice of tape or your finger messing up what you just shot - The only time I'll pull tape up is when I'm using enamel based paints or One shot - or in rare cases final clear - reason being is those types of paint are not suited to fully dry and then pull the tape off - it'll crack and chip...
As far as shooting your paint - Only shoot one what you need - If one coat works, go with it - if you're shooting something like yellow over black - try using a coat of white first then shoot on the yellow - You're always gonna run it to bad paint edges, but if you think about what you're doing before hand you can usually come up with a better solution. I've had my share of triple and quadurple sessions of clear and have sanded my you know what off trying to get it as flat as possible - But that's why we can charge the big bucks!!! --- Good luck - Bones!~