Well, after the American revolution we continued to conquer and colonise until we owned a quarter of the globe and governing a higher percentage of its population. This statement alone disproves your original point that the American revolution led to the British empire unravelling.
Every point that Guitarguy makes could easily be applied in the other direction. I could copy out his statement and use it to support my own side.
While I will not disagree to the point that America has an influence on Britain, that influence is nullified by the influence Britain has on America. Thus, it is stupid for Guitarguy to claim that Britain should thank America for "food" (etc).
"You are full of shit when you say that you didn't call him an obvious troll."
Well if he isn't a troll he must be stupid.