So, I've got four ideas that I think you may find productive related to the position of gang leader. I'll go from least to most important in my mind. The first one isn't so much a suggestion as much as it is an area you might want to look at. As the game is now it takes 300 gems to become a gang leader. Although it isn't impossible to get that many from game play, most people will be paying real currency for them. Aside from personally seeing that the gang is managed well (hopefully leading to better boxes for all) there's not really any return on investment that I can see. You might consider raising the amount of gems required for the position, but in turn offer the leader a personal reward based on how well their gang does.
Second,as a gang leader, I see it as my job to try to get my members to do their best. It would be nice if I could offer a small reward to the members that do the most. I'm thinking something along the lines of a top 3 or 5 leader board that the other gang members can see. A VERY small prize of gold or gems might be awarded as well. These top members would be picked by the gang leader, and the cycle might refresh every 3 days or so. Probably it would be best to put out a new one after the gang battle cycle has just finished so that total trophies can be included in the placement. I recommend keeping the prize small or none at all so that the system doesn't get abused. I know that trophy counts are available now for all to see, but it just isn't public enough for my taste. It also doesn't factor in someone who hasn't contributed many trophies, but has been consistently ranking up.
Item number three has to do with the gang settings menu available to the gang leader. There is currently an option to choose the prestige level of those allowed in, but I'd also like to see a toggle on/off switch that would allow gang leaders to require (or not) that new members cannot be below the rank of the lowest current member. The primary job of a gang leader is to decide who gets kicked, and once they do kick a player, that space is usually filled right away with a VERY new player. That can be tough on a gang that is mainly comprised of higher levels. It just seems like a good tool to make available to the leaders.
Ok, time for the final, and most important point. The gang's leader has one very important job, namely to decide which members need to be kicked. It is currently almost impossible to make that decision fairly. Gang leaders currently have only TWO ways to know how useful a member is. First, is trophies earned. Second, is chat activity. That's really not much to go on. I believe that a brief bio page should be available to the gang leader in order to judge performance. This page should include how long they have been a member, the last time that they were online, total trophies earned, and how many ranks they have gained in the last week. Although ranks gained doesn't directly affected the gang, it does show an overall interest level in the game. That doesn't have to be an exclusive list, but I think those are the essentials. On a related note, it would be nice for everyone (members and leader) to be able to see who else is online on the members page. Wow! That was a lot longer than I had intended. I do hope that you find at least one of these to be helpful. If it looks like you might use one of them would you let me know? I'd like to know that I've been helpful. Thanks for the help Nick!