What to do with idle neighbors?

I've been deleting them when I have a friend request to replace them...since in some cases I can't be *sure* that they're idle (as there have been people who might have been deleted who then visited my town and were available for tapping). So I had 7 friend requests, so I deleted 7 of the seemingly idle people and accepted those friend requests.

If I get more friend requests I'll likely delete a couple more idle folks.