2) A lot of space is wasted in this site. The whole left column, which is about 40% of the site, is completely blank. I have mixed feelings about the little feedback bar, which, being a black log and over a yellow background, reminds me of ___.
3) Eventually you'll have to start making money, and thus putting up ads. The nice thing about wikipedia is it is non-profit and doesn't serve ads. If wikipedia did serve ads, I probably wouldn't bother contributing.
4) You should study the usage patterns of wikipedia, and what made it successful. I think there was an essay about that somewhere. The conclusion is that most of the edits come from a small minority of hyper-dedicated users, and the general high quality of writing on wikipedia can be attributed ot them. How are you planning to attract those types of people?