screw that, launch. launch it and control your workload by controlling your marketing plan, trying to keep the number of users in check with what you can handle. then polish it.
Seconding this. You're not going to have a perfect site specifically because you haven't launched. Without audience feedback, all you're doing is endlessly second-guessing yourselves - that sort of feedback exacerbates any existing groupthink behind the design, potentially causing it to be far less usable than it originally was.
Third, launch then get feedback, interate quickly. I was scared when I launched my startup, but you will realize it takes time to get users to try your service out. We were lucky to get techcrunched before launch which led to a bunch of signups for our beta. So we had about 2000 users on our list prior to launching.
