Just a quick two cents:
Last month I spent an afternon with Wiseau questioning him about the film and getting a feeling for the man. I also spent a good few minutes helping him find his car in the car park, which he'd lost. It took Greg Sestero and I at least 10 minutes to find the car. Eventually we did. I returned the next day to a screening where he met the fans, and spent about 15 minutes signing stuff.
My verdict? He's just an extrememy odd, naive guy. Not a dodgy bone in his body. This is reflected in the film he made... it's just an insane kid making a movie.