I think that the mobbing situation would be solved if 1. the flag's return timer gets set to 10 seconds or so and 2. the flag dones not move when it hits the ground, which I doubt will be the case.
The problem with a new mode like this is that there are multiple ways to solve the problems. However, the developers must choose those that create order and prevent most players from working their way around the implementations, which is of course the natural thing to do.
Allowing the rabbit to throw the flag in a kamikaze effort to create massive chaos would be a great way to spice up this horrendously boring game mode :3
It's only boring if one is not good at it. And people who wander around sniping are not going to get better at it.
Your solutions would cause more problems and solve none.
1. Flag return timer set to 10. Okay, queue lots of respawning around a stationary flag and a pileup waiting on the return (as it is now, I've seen 10 people dueling around a stand that has no flag on it).
2. Stationary flag. Right, so you want 1 person to grab with 13 others shooting at him, killing him instantly. How well does that work on a flagstand in CTF?
3. Throwing flag. As often as I've wanted to add this, it would break the game even further. Especially, people who know how to toss, grenade jump, and catch (who are already on average better than most) will have an even bigger advantage.