Yes, if the WordPress dashboard runs slowly but the site loads quickly, my first steps to troubleshoot would be to disable plugins and see if that makes any difference. If it does, you’ll want to re-enable each plugin one by one to see which one might be the problem. If it’s not a plugin issue, you might want to check your theme as well.
Unfortunately if the issue is with the plugins, our tech support team cannot provide support for that. I’d try posting in the WordPress support forums for any advice as well: http://wordpress.org/support/
I didn’t see your update! That’s awesome! I noticed you have quite a few plugins installed. It definitely is beneficial to delete any inactive plugins you don’t need, and update the ones that need it. Glad it’s working now. I also replied to your open support ticket.