sorting through the dogpile on craigslist isn't any different than other venues. if ur not good at judging character in a bar or at a party then ur not going to be very successful on CL either.
I've had quite a few good connections, granted they were for a quick wank/suk toss in bed but all have been fun, and i'm eternally curious about guys and what makes them tick so for me exploring new territory is primally satisfying.
as far as your friend/roomie goes OC i think maybe the fact that he had a sex addiction problem might have skewed his results.
my screening process goes something like this:
initial email should include pics, not xxx but at least face and body, clothing optional

and cell#, a short fone convo can tell me more than 20 emails.
meet in a very public place, in the event he's a total fake/psycho you can easily abort the mission without trying to leave his place or get him out of yours gracefully. And if he just turns out to be somebody you dont' feel the chemistry with, dont' be an ass and make up some lie, be a human being and tell him that.
keep expectations realistic: you're not gonna marry this dude anymore than u did the guy u used to mess around with in hs. so have fun and enjoy the moment, if anything else grows (that doesn't require anti-biotics) then it's a bonus.