Sry im right by you. It is a good solution. But with offline payment its more complicated. I gave you an example (table above) what i expect.
At the moments it seems the offline payment havent a recurring support.
It is important to manage the payments for the offline payment user to see payment is open and set manually to payed and when is the next payment date and this one is visualized and notified to admins and user. Thats the full control of memberships on offline payments. I hope thats decribed my wishes in a right way. Sorry thats not my origin language. I hope we can bring the membership forward to the best solution for offline payments.