A flawed man most definitely. From the timing of things it looks like the Feebs were nosing into his affairs well before Benghazi happened, because a nasty cat fight over him was going on.
But he may have some interesting things to report. At this point risking his career is moot.
Agreed they were nosing in on his affairs, and that there was a catfight, of sorts. But I'm not sure the catfight was over Petraeus. I think I read that Broadwell was trying to scare Kelley away from Allen.
Fairly small group of people involved there, but don't assume Petraeus is at the center of it. He might be, but at this point the evidence is ambiguous.
I don't foresee any interesting fallout resulting from his testimony.