Good thoughts, one can see that you deal with the platform and that you search for possibilities to improve the platform.
I like the concept of implementing a second pool for the flags. I think this would definitely lead to better balanced rewards.
On the other side I can relate to the comments of @aggroed and @jasonyoakam, because I can also imagine that this would lead to flag abusing.
All in all I would go with your idea.
Especially the point with delegating downpower seems very interesting for me.