Aha, for the last issue, I think it was the background-attachment. For some reason, it was being set to fixed. I’ve changed it here:
Not sure why, since my understanding was that it defaulted to scroll?
So, should I attach your jQuery to the onReady and/or the window.onresize?
It’s strange there isn’t some in-built CSS behaviour to take care of this, I would have thought this would be a fairly common requirement.