As far as the OC/CC issue you seem to have that covered with the licenses you have, Pa, Delaware, and Virginia are all OC/CC states. Carry as you wish.
I believe that Virginia requires that you OC in restaurants that serve Alcohol. Pennsylvania( either way is OK), and Delaware(no bars but TGI Fridays, Red Lobster type restaurants are OK.)
Maryland is a completely different world. When carrying through MD keep gun and ammo
cased separately and I personally lock both cases to make any illegal search that much more difficult.
The link below should help with any questions you have as far as prohibited areas and
links to actual statutes.
Disclaimer: Everything stated is opinion and not to be taken as final word on the subject. please verify all info on your own.
have a great vacation!