The BAC story was a popular one to promote the idea of a conspiracy. Rumors always start in these situations and get reported by journalists eager for something to say, like when Carnahan's crash (and just about every other crash) was initially blamed on icing. The BAC story, from the sources I've read, is largely debunked even by conspiracy buffs. See:
http://www.rense.com/general14/brother.htmThe death was suspicious because of who it was, and the timing. Not just the October Surprise, but the BCCCI scandal--the head of BCCCI was connected the the other Bin Laden, Usama, through marriage, and was also connected to Salem (IIRC) through an airport. Add in Abbie Hoffman's suicide after investigating the matter, and it's hard not to be suspicious.
Here's the thing that makes me most suspicious about the whole Bush family. Salem bin Laden was probably an investor in W's first business. He was close enough to the Bush family to be linked in rumors. The BCCCI scandal linked Bush and the Bin Ladens. At roughly the same time as Salem was giving money to W (a little later), his brother was receiving funds and training from the US in Afghanistan. Okay, skip to a different story. Reagan is shot by John W. Hinckley. Hinckley's father was a Bush donor in the 1980 Repub primaries. Hinckley's brother was supposed to have dinner with Bush's son Neil the night Reagan was shot (verified publicly by Neil--no questionable theory in anything I'm stating here). John W. Hinckley lived in Lubbock at the same time W. lived in Lubbock, and not very far apart. George W. claims he never met John W., but George has a documented history of lying, even under oath (James Bath, during a federal investigation in 1992), about knowing people he knows. There families were friends at the time, but supposedly no one told the two Ws that they lived a few blocks from each other?
That's a lot of direct coincidences. Not vague second and third degree coincidences, either. Most conspiracy theories sound like the Kevin Bacon game, but in these are direct links.