Heh.
I don't have a lot of time, so I'll make this quick, but I think JTB should at least be seriously considered for the shot.
The only one of AB's points that I found incriminating was the Circus interactions, but I think the WIFOM aspect prevents that from being enough.
Ryker's general unhelpfulness early on is basically exactly what he did in Time Travelers, and the whole "He doesn't volunteer many town reads and is okay with half the game dying" fits his play from there almost exactly, he was okay with just about anyone aside from himself/Nabe/PLSD dying late D1.
As to JTB, I need to take a look at why he hopped on Raziek, because it's FAR scummier to agree with a bad case than to make the bad case, the person making the case can often tunnel, and are often biased to think the case is better than it really is (trust me, it used to happen to me all the time.) To independently agree with a bad case is much scummier, and I want to take a look at JTB's reasoning.