I will never ask anyone to hurry up! (I wonder why...)
As far as I'm concerned, take your time writing your characters and finalizing things for the game...
I think more than just the warrior-types could be with Balin at the Mirromere, couldn't they? Obviously they are still wary of dangers, but there has been peace for a while, and Balin's purpose is simply to see it...couldn't others tag along because they want to see it, too?
On the other hand, I can see Balin and the leader-types, or the warrior-types, not allowing it all the same. I especially can see them not allowing the women...
And I suppose there is the simple limit that you can't have a whole bunch of dwarves following Balin around outside... So perhaps limiting it to a specific type - the 'military leaders' as you called them - is the best way to go,
Groin, to keep it simple.
Anyway, just my bit. I'm fine with either way. I do think not all will go/be allowed to go with Balin, of course, and I'm sure those who aren't along will find plenty to do before all hell breaks loose.