"We strongly recommend using Sixfeet with Chrome". I wonder what issues you encountered with Firefox, that you strongly recommend against using it?
"Continue with Facebook" or "Sign in with Google"... sigh. Perhaps I'm atypical of your target audience, but for me, that's a really high barrier of "do I really want to deal with this?". Brainstorming remedies, perhaps a demo video of the site in use - the desert cart showing the tempting dish, rather than just the menu sketch with its imagined potential value severely discounted by uncertainty. Or more login options. ;) I wonder if a no-login immediately-visible public onboarding lobby, perhaps with restricted hours or population thresholds, might somehow be viable.
A meta topic, is how to make sites like this more easily visible to their target audiences?