Clan wars temporary opt-out
Everyone has real lives even if they enjoy playing clash of clans. Often there will be one or many clan members not participating in a clan war due to such reasons as vacation, or just being too busy to log in and fight their 2 battles. For many clans this means that these players are just taking up a war spot and not doing anything with it (no battle means not earning stars for their clan) and also means the enemy has one (or more) person to attack who won't counter attack. So far the only way around this is to kick people out of the clan before starting a war, or ask them to leave if they will be away for a length of time... Often this results in hurt feelings and other problems.
my idea is to allow clan members to set an opt-out flag so that when the clan enters a war they will simply be observers until they switch the opt-out off ( and then will be again eligible for the next war) this would allow people to remain in the clan, save some hurt feelings, and reduce the possibility of clan members who will not be attacking. This doesn't eliminate the problem, but I think it's a great (and easy) way to improve the situation.