Hi ara,
Thanks for this. I've looked at all of this that I can, and whilst the speed of the site is indeed poor, more worrying are the error messages we've been seeing. (links below)
I should also point out that I'm on a Managed Wordpress setup through goDaddy so it's a shared environment I'd imagine. However GoDaddy say all is well - I don't have access to see what the intance is doing resource wise unfortunately (and I haven't found a plugin that shows me that info).
My entire point with all this is that everything was fine, and the only thing I haven't tried is removing SSL; I've restored the plugins, themes, config files etc all to a good month prior to see if that helps. It doesn't.