lardconcepts:
So instead of me just complaining, perhaps I can help a bit.
Pleased to see your collaboration 
The version of mootools is from 2006(!!). Why would two overlapping frameworks be needed? jquery should do everything.
Good question, the response is "I don't know". Mootools seems required by the current SMF's theme but it is unclear to me the usage, I will try to disable it on our development instance and see what it happens.
About using Google's CDN for jQuery: you are absolutely in reason, the test for migration to 1.8 is in my schedule (since far too long time, really).
I've be interested to know about this bad performance and what the conditions were.
I've observed the experience of a friend of mine, on a small media coverage website with low traffic (peaks of 50 concurrent visitors).
Too often the HTTP request failed in an error by Cloudflare complaining it was unable to find the target content, and very little hints was provided to correct the issue.
Not a so good impression...
This morning I began to put a cache plugin on the Wordpress instance driving the Arduino blog, just to provide a quick and dirty solution to the still moderately high traffic driven by the latest post published. And the Varnish documentation is opened on one of my browser tabs, ready to be implemented on the development server in next days.