I'm still surprised that such an old-fashioned system(trust,thread,ip checks, 6mins cool-off periods, etc) exists + absence of social networks integrations(likes/follows) may scare some users... Sharm...
I think they will be just fine. Any half-wit internet used is used to systems like these; and if not,it's fast and easy to learn. Not every page in the universe has to have a damn like and twitter button, and you DO NOT have to share anything you do with every one of your friend's and faith acquaintances. It is just not necessary
Also, since this kind of is a financial site; would that make it less serious somehow... wait, what am I saying? I really have no idea
ON THE OTHER HAND
maybe if people linked their FB profiles, people could more easily see that the individuals are not spammers or other riff-raffle. But it would be pretty strict to require it - not everyone uses Faceboojk
those are my quick "stream of consciousness" thoughts on the matter