I guess I see a few major differences between this and friend-of-friends. Most important is accountability - a friend-of-a-friend isn't likely to send me a creepy/sexual messages, since there would probably be social consequences for them from mutual friends. There's no such social barrier for people I don't know at all, so the only consequence would be me blocking/reporting them (and you can easily make a new Facebook account if that happens).

For members of groups who I might not know - yes, people in groups I'm in know my full name, but probably don't know enough about my life to make it worth behaving creepily towards me - and if they did, any actions would likely remain virtual. However, your service is telling people my full name, and states that it will "sort by location" - so now someone knows my name, knows around where I live, AND knows that I am single (so it's more likely that I'm not living with a male)? That's not information that I'd feel comfortable broadcasting to people who have no accountability.

I know I'm focusing on the creeper/stalking issue, and I'm sure that's frustrating feedback when the majority of your users will be using this service with honorable intentions. I'm just trying to explain why I and most of my female friends would be instantly turned off by a service that shares this information - and from what I've read, attracting female members is a huge issue in the online dating space. It's really something you should try talking to female friends/family members/a focus group of potential online daters, because I don't think it would be an uncommon point of view and you don't want it to keep people from joining your site.