I put my CJ links anywhere I can! The 'site' thing is more for you to track your links.. because if you put the same link on 20 different sites, how do you know which sites are doing good and not so good?
You can place text links or banners anywhere you want. Text links convert better than banners, so keep posting text links in articles and review sites.
I wouldn't do it, since it can cause problems and issues that may later raise up a red flag in the system...