i am changing original color so while i have the doors off i want to paint the door jambs and door area.i would like to use bc/cc. can i paint and clear at the same time,but paint the exterior some time later? would it hurt anything doing this at differant times or should i wait to do it all at once?

Not a problem at all. You can prep and paint doors, inner fenders, hood and trunk area. ALL B-4 you paint the car.