Here's page 12 of Fusion #11, and we get a tidbit about Brooder and Dandy-Lion's past here. Check out the interview with Adam Conroy (starting on http://theduckwebcomics.com/Essay_Bee_Comics_Presents_Fusion/5461316/ ); you might be able to start filling in some of the holes in his story that Savunn points out in her notes.
Black Rose--Probably. I haven't scripted the scene where some explanation might be given, so I'm not sure how that conversation will flow yet. Gotta get to the scene before I see what everyone actually says. (But explanation may be given in Issue #13.)
The U.S. has no such agreement with Darmar. In fact, because of Darmar's horrific human rights record, the U.S. actually has sanctions against Darmar (which is why the agreements Lord has with the country, as Dandy-Lion said, are buried in secrecy). Regardless, Darmar's sovereignty is protected by international law.