What about expanding the ranks and have another spot for Co-Leader?

That would be the next in line for the leader spot and could take the leader role if the leader becomes inactive for so many days or if he or she gets enough votes to replace the leader at that point.

Have all the perks the leader has except a few like disbanding the guild.

As for the ranks the leader should be able to customize the names for each rank...

Just throwing ideas around...