If I paint a large side of a stucco house with a large napped roller with an acrylic latex, how do I prevent overlap marks occurring as I come back into dried paint? Or will this not happen?

If you work in the shade and not direct sun as much as possible that will help a great deal. There is a product called Floetrol that will slow dry time of the paint to help in reducing lap marks. Also the flatter the finish of the paint the less chance of having lap marks as well. If you do these things and move along at a good pace you should not have a problem with lap marks.