I guess I would prefer that your age is never deleted and that "paying what you missed" would just always be a (reasonably large) flat price, whether it's been a couple seconds or a couple months. Also, we're talking about in-game items here, not real money, right?
Ya I could see that, hardcore mode should be instant deletion, softcore a week of no power then deletion but with a set amount of "rent skips", softercore would be just power off until you pay.
Hahaha yes, only items in game