A check reveals that my site takes about 8 seconds to load.

I have WP Super cache installed.
Errors include no width or height dimensions on images, yet most are from ultimate Facebook.
Also, it suggests I minify my css and js. Super cache has minify built in and checked. When I try to activate cdn, using a sub-domain the site looses it structure.
I would load more plugins but there's no point if the site is so slow.
Could really use help here. thanks.