I don't think the online thing is all that hard at all, it's taking it offline that's the hard part.
I've had my fair share of fake profiles, BSers, and phony people, but I've also been fortunate enough to have met some of the lovliest ladies on the site as well, and even some in person.
The biggest thing is to be serious, and actually meet, whether it's as friends, or something more. No point in wasting anyone's time sitting behind a computer for the next few years, with no intention of ever taking it any further.
RE: Haw many vegetarians/vegans are on CS?
I have heard that before.