plus the fact that people could multi account to vote :/ then delete them
This is a possibility for any vote, don't see why that would influence this one.
Imo this isn't really necessary, considering it's the admin's job to delete a dead clan and that if the clan is still alive, and official, it shouldn't need a second test.
Yes, this could be quite useful.. but this will only clear us of the noob and dead clans for a while, not a long term solution. They will probably keep circling forever unless we get some stricter entry criteria.