Iraq is a big country, and I can't offer solutions for the whole thing. The corruption there is a tremendous problem.
What I can say regarding these areas that are minority populated, like Sinjar and Nineveh, is that if you had these commissions where, say, several representatives of a few western governments were included in a small body that was present on the ground and monitoring the implementation of reconstruction and humanitarian work while working on the political side simultaneously, they could be coupled together: humanitarian work reconstruction and administration and institution building.
These groups would be on the ground watching how the money is used, supervising it, basically. I think that would be a tremendous boon. They could be interfacing with the Iraqi government, giving respect to them and making their officials feel involved, but also policing it in a soft way.