Alright, going from bottom to top.......
Render: I like it suppose but it's quite rough. If you were a good little bunny and saved the .psd with all the paths then I'd help you cut the edges cleaner. Being that was your first attempt I'd say it was quite a nice job, better than my first attempts. On second thought, what technique do you use?
Drawing: I'm no better, so I'm not goona critique. Reminds me of a little drawing Aqua did once xD
Wallpaper: LOOKS fine, but can I have a link to resources? That way I'd have a better idea of just what you did.
Temp: Looks cool. It's fine for a small affiliate thing. Why not make a userbar tut instead of leaving it so small?
Sig: Very Basic. Not alot of effects. Try using C4Ds more and...Well search
deviantart.com That's a good site for all your tutorials.
Userbars: Plain but gets the poitn across. I like them but they need a border, ynless I'm going blind here. Do this if you have PS:
1. New layer
2. Select all
3. Edit(?), stroke[inside, black, 1px]
Simple but better than nothing.