#I feel the previous place where the login and logout dialog box was located was convenient.It's sometimes frustrating to scroll down every time to login or logout.Hope this suggestion will go noticed.

#The dropdown menus in the top of the page sometimes annoys by repeatedly showing submenus.I feel that if the overall dimensions of each tab be reduced,the problem will be solved.

#frequent review and approval of articles would help since we've to wait each time to see if the article gets approval or not and then edit it.

#The points system can be improved by considering the points for some monthly contest and then at end of each month,the points may be reset.
# as suggested by a user already,the limiting of polls is necessary, there are all sorts of polls out there that are not active at all.To improve posting quality polls, restriction of posting poles by number of polls or review or you can add people verdict so that only good polls are posted and the unnecessary ones are removed(like in yahoo answers people decide which answer is best)