how big is your tank? these cichlids get to be around 10-11inches, they should not be in a tank less than a 55g, that would only accommodate two BP's, every addition would probably need another 15-20g, so please think about that as well
as for aggression, its normal with cichlids, my bigger one which is just a tad bigger picks on every cichlid in my tank, just because hes the biggest
also, Blood Parrots are really shy, my blood parrots took two weeks to get comfy just to eat in front of me and for them to go up to the glass to see whats up outside the tank, this actions usually have BP owners questioning if they are sick, but they are not, just give them time
live for the moment, cause you will never know if you will have a future...