Yes they could get married. All that matters with blood is if you have it directly transfused, for A can only accept A and O blood, B can only accept B and O, AB can receive All blood types, and O can only receive O.
Marriage has no effect between blood types.
no
yes
no
NO,
Yes.
yes
yes
see a doctor for such questions
yes
see a doctor for such questions
no problem
you can marry anyone you want