The cories should be fine, but if the mollies come too close to investigate, they could get hurt pretty badly. Also, the addition of other fish sometimes stress the parents out to the point of eating the eggs or the fry. A lot of people use a tank for just the breeding angels to breed in. Some others set in a piece of slate for the angels to spawn on and then remove the piece of slate to another tank to hatch the eggs and raise the fry.