I am staying at CSS for 6 days and debating whether we should split with CTI for 3 of the days. If we do a day swap and like it, can we do it more than once during our stay. Do u have to adhere to the normal departure times?
How does this affect the romance rewards (free massage, etc)?
Only if you pay for a day pass. The Trading Places program (if you're registered with the Romance Rewards) allows you to visit a sister resort once during your stay from 10am until 4pm and take advantage of all the other resort has to offer, except for anything that requires reservations.