Ok, I'll reply directry to your questions...

Your first impressions?
The general appearance was good.

Does the site load fast enough?
Yes. No problems with it.

Is it an interesting concept?
Yes, I think social networking is a really hot word today.

What have I done right / wrong ?
Hard to say.

Should there be any additional features?
You have hot-or-not, blogs, shops? Should there be more?

How about the graphical design, is it good?
The general appearance was good.

Have you ever heard about UbiBay before? Where?
Reminds me of Ubisoft