TLC suggestions

I think there is no need to limit the number of players. Especially for a game that is basically 99% DEAD. As long as they know the basic rules of the event, anyone should be welcome to join.
Let's say you set the max number of player to 6 and that Sunday 8 guys are on TS waiting for the game. What are you gonna do? Pick 2 and tell them to go play elsewhere? I bet those two won't be coming back the next week-end.

About the "keeping everyone busy" thing, I really don't see an issue there. At the moment you decide to join the event, you know that you can't wonder around as you would on a random server. If you can't accept that, just don't join. There are other servers with plenty of slots waiting for you.
If the mission requires you to hang back for a long time or doesn't allow you to kill dozens of enemies, just deal with it. Again, if you're bored, then it's your problem. No one pointed a gun to your head forcing you to join the game.

That's my opinion.

It's not a question about to limit the number of players but to limit the number of players in one team and to create a second team if needed. Really, i think that 7/8 is a maximum in a team, more it becomes very hard for the TL, not necessarily to keep everyone busy but just for managing the team. It's difficult enough to simply manage such a group and always remembering who plays and with which weapon and with which role.

It will be funny to test something one day : Let's imagine that the TL doesn't move from the start point, managing his team and the full battle only by looking at the handmap

Also, Snow, don't forget that it's true that you are also much familiar with the role of TL than lot of other players, including myself, so things that seems not hard can be hard for a new candidate to the role of TL, because it's really another behaviour, another kind of reflection, another global vision of the game that the TL must have and that need a bit practice.