Finished this last night, and I really enjoyed it.
It features a very realistic, IMO, scenario of what would have happened if the Dominion had taken over. They're not just overlords, they're insidious. And you look deep into human and Cardassian mentality. As it is, humans are very slow to change, add to that the Graft, and the Dominion would have a very firm hold.
The breaking of the Graft I found fascinating. It's very realistic- and a method many people use to conquer phobias. And you describe it very well!
And you gave us an optimistic ending, which is nice! I don't think, with Phase technology, the Borg will stand a chance!
I do doubt that the Jem'hadar will all die- I think that once that aren't addicted to White are far more common than the Vorta believe.