My suggestion is that GMs should be able to modify the hierarchy inside a linkshell, should a situation such as the leader becoming banned.
http://imgur.com/vhKYWd9 (a screenshot of myself being assisted via ticket.)
It seems like something a GM should be able to assist with, quite frankly. No offence intended to GMs or anything, I appreciated the assistance I was given, but it does seem like something that should be within their power.