I suspect this has been suggested before, but I can't be arsed to go looking for the threads.
It would be nice to have the option of nominating clan members to assist in various clan leadership duties. Also, this should be broken out based upon the responsibilities; (1) setting up challenges, (2) moderating the forum, (3) recruiting, (4) kicking out members. A clan leader could nominate a vice-clan leader empowered to do all of these, or could nominate different individuals empowered to do one or a few of them. The clan leader would retain ownership and be empowered to continue doing these tasks as well, if (s)he chooses to do so.