I've never done it, but I imagine it depends alot on who is putting on this speed dating event. I know the SGA at my college puts one on, that one probably has a lot of college girls. If a church put it on, that would have a lot of religous types. Getting the picture? I imagine you'd get a lot of psychos if you did one advertised in the city paper. It also depends on how old you are, if this event is for people 35-40 you can bet she's expecting to maybe marry you, expecting you to be everything she hopes, and watching you very closely and critically.
But the concerns you have aren't really valid, psycho girls appear in every walk of society and you can usually tell pretty easily if you are dealing with one. The speed dating thing, I reckon, would be tough because:
1. You're instantly acknowledging you have trouble getting women, that you 'need' a woman.
2. You're being lined up and compared with other men in your age range. Look honestly at yourself, can you compete? Are you in the top 10% of those men? if not I suggest getting some normal 1 on 1 interaction.
Personally I WOULD do it because 1. I'm top 10% 2. Psychos don't scare me.