(Btw, I would really like to know why the bandits want to move into another kingdom... a reason why the players/PCs would be convinced to join them or turn them in. Reminds also of the Swordfish movie.)
Running the group:
- a good middleman could be a... woman. A consort shouldn't be suspicious, but can be easily laid blame on. But guards are also fine, since they are the ones he can trust most.
- I would make him the useless man on the top, that tries to do things well, but most people around find ways to make it better. While Griffin should annoy the players several times, he could also reward them highly for some trivial deed. Contempt should be the key feeling.
- Also, spread rumours that he can be easily influenced. His chief advisor should have the greatest power in town - which is actually in Griffin's interest.
- So a well-meaning, but inept man on the top. I would avoid giving him a stutter, though.
- I like the monastery being run by the group most.