Are you allowed to live with someone in a romantic way once you are separated after Oct 1st?
The new law that goes into effect October 1 does not govern all acts related to paramours. It merely defines the types of behavior upon which an alienation of affection action or criminal conversation can be based on.
Before the law goes into effect post separation acts could be used as a basis for a claim, the new law changes that, and states that post separation conduct can only be used as corroborating evidence that an affair was taking place prior to separation.
As for living with someone, it could have an impact on your custody suit, (alimony claims if any), and adultery is still listed on the books in NC as a crime.