You make a good point. I'm not on many other forums, but the one I'm one apart from this are all set up like the mincfraft forums, and they're complex and dull. This is different, and more friendly.
Yeah, signature boxes are sometimes annoying, and they make the forum look cluttered, and it makes the loading time slower beacuse of the pictures.
I second what @Fast-Driver said, signatures (especially ones that are 200 x 200 pixels large) completely consume the connection that was suppose to go into loading the crap of the webpage.
I think signatures can be useful and a great way to personalize your identity. However, they are often bulky and does not at all go with the spartan layout the forum currently has.
Perhaps customizable text next to the "Permalink"? One could add ones favorite quotes or something like that there. It's just dead space at the moment.