To me, the forum header actually looks really nice, and suits the theme. Forum listing wise, you may need to post a bit more in some of the forums, as while they don't look so dead any more, it looks like three quarters of the site activity is revolving around one or two of the forums while the rest are just left unused. My suggestions now are mainly:
Have some football related forum icons instead of these to match the other images:
Add some football related smilies, as there are some out there, and they'd be better than just keeping the default smilies like you've kept now.
Might want some custom BB code. Not sure what, but if there's any major football resources, sites or video sites, BB code for them would be a really nice idea.
You've got some avatars, but I think you should add some football ones (players etc) to the default selection, just in my opinion.