Really well put, Gary. I was thinking how I would have formulated things, and couldn't have said it better.
As I approach the 2 year mark from diagnosis,I find that I spend less time focusing on recurrence possibilities, but it is never completely out of your mind, and there is the ongoing fibrosis and related stiffness, xerostomia, etc., to serve as a reminder that this is not a cavalier endeavor. My follow up appointments with the surgeon, RO and MO fall about 5 -6 weeks apart, on average, which means that the mind is never clear of the thought -- hence my total concurrence with your "you are never free of cancer" remark.
With Ohio drivers, I figure my chance of being 86'ed by one of them is about the same as my recurrence chances, so try not to spend too much time worrying.
Great post!