Tape should be removed soon after painting, as for the chipping part - I don't know if there is an answer to that, I suppose if you are going to be clear coating you could run a very sharp craft knife over the edge of the tape, this would at least prevent the paint on the un-masked side from chipping. Regarding the paint on the underside it might help if you remove the tape in quite a warm area as it will soften up the adhesive slightly & may help prevent some chipping.
EDIT: It's advice, but I'm no expert!