While some of these ideas are interesting and I agree with the basic sentiment, I think it would be challenging to build up enough of a social graph to bootstrap such a social network especially when people are automatically erased when they don't regularly use it.
Ah, made me realize, if the network is meant to promote connection, it shouldn't strongly delete them, but perhaps move them to a "stale" / "inactive" list. Thanks!
People have a hard enough time making real connections without artificial barriers being thrown up. This sounds doomed from the get go to me.