Is there any reason why you both have to date the same woman? You might find things a little less tit for tat if you were with different people.
As for the woman who lives 5 states away, spend a lot of time with her irl before even considering moving her in. She would have to give up her whole life where she is to move in with you and that's no small undertaking. Also make sure she has a plan to support herself when she does move. Money troubles put a lot of additional stress on a relationship.
Everything will be ok in the end. If it's not ok it's not the end.