Add way to recover leaderless clans
If a leader drops out without appointing a replacement (loses interest, run over by a bus, whatever), there is no way to get a new leader for the clan. This has happened to a friend in CoC, and to me in another game (rules keep me from naming it). The "orphans" tend to lose interest in the game and drop out.
Why not add a rule that if a clan leader doesn't log into the game for a specified time (a full league season without playing would be a good starting point), they get dropped to co-leader and one of the active co-leaders (doesn't really matter how they're chosen, so long as it's consistent and documented - random, most trophies, most experience points, most war stars, or most money spent on gems are a all possibilities) is promoted to leader. If all co-leaders are also inactive, promote an elder to leader. If all elders are inactive, promote a member. If everyone is inactive, do nothing, since in this case an inactive leader isn't inconveniencing anyone.
This would allow re-establishing the chain of command in the event that a leader drops out without appointing a replacement.
BTW, good job setting up a tight, efficient game. Some competitors' games are hogs - the one I hit the "leaderless clan" problem in, I uninstalled because it burned through 5 gigabytes in a month. That same month, even with intensive play, CoC used less than 100 megabytes.