what I'm getting at with the minimum of 7 people to start and make the clan active, is that a clan should be created when a group of people get together and say, lets all start a clan.
If you don't have enough people, then you could do a similar thing to what's on most games and start a thread in the forums saying that you're starting a clan, and looking for at least 2 members for so and so area. Don't think that no one would want to join. It's a great feeling to join a new clan, and be there while you push your way to become well known and a big an powerful clan.
Anyway, the whole idea is, you should already have your 7 people Before the application is posted. It doesn't matter if it takes you 6 months, so long as you eventually have at least 7 active members at any one time.
My reasoning for if a clan becomes inactive, is that people will all the time leave the game without leaving clans or even telling anyone, they'll just stop coming. Now, if it's just an ordinary member then it's no problem, because the leader can just try to contact them and ask if they're planning on coming back (if not, then they can remove them from the clan), however, if it's the Leader that suddenly leaves, then everyone else has two main options. Talk to an admin, and ask if they can change who the leader is, (the Admin would obviously have to check that the person had really left, and a mutiny wasn't taking place)
or, they might do what I suspect most would do, leave the clan and find a new one.
Eventually, the number would drop below 7, and the clan would just sit there, inactive, and taking up data space.
Hence the deletion after a set time period. Doesn't have to be 30 days, could be 60, or 90, but it's the same kind of thing that happens with free email providers. "If it's not being used, why is it there"
What I'm finding amusing is how much detail we're going into here, considering such a feature would doubtless not be very high on a to-do list (though it is very cool and very useful, it's not critical to the game running).