Freesite 404s?

[romeoboi]

hey everyone-
im setting up some freesites, and I was wondering about whats allowed with 404s. I will be setting it up so that the thumbnails go to the picture file themselves, and not a html page that displays the full size pic as it standard. However, I was wondering if I put an offshoreclicks popup on the 404s and Access denied errors (as I will be setting it up with htaccess that you have to click the link to the pic and you cant type it in) was allowed? Will putting a popup on the error pages stop me from getting listed?

thanks!