Don't give John the rights to recruit players. Don't let more Johns join if it's a big deal. They can find an active FC instead. Kick anyone out who isn't you and close friends you trust. If you want to keep a solo fc to just you, that's really the only way.
Also, if you want to override the 1000 char cap, you can edit after posting to add more.

I, too was in a FC where the leader stopped playing about a month in until December. However, we're all real life friends. So once we decided we wanted a house, we just called the guy and asked for him to pass lead. If we didn't have that option, we would've been really upset if we had to remake and relevel to get the house.