I think you mix a bit different topics:
Nothing really unusual, since that was the standard Napoleonic response from the beginning; in 1796 Italy his orders are filled with demands to "make examples." Terrorizing the local populace into submission was a basic Napoleonic operating principle.
2) As far as I can see, it was standard procedure for the Napoleon's Armies to live off the land and to plunder anything and everything along the way. This was not an accident but was instead part of N's basic strategy which enabled his forces to move quickly and not be as burdened with the requirement of having to feed and provide for his soldiers. The basic soldier in N's army was a master as foraging for himself; after all, he had to be or would have starved along the way. While this strategy was a tremendous advantage for Napoleon it was also, IMO, a basic flaw that eventually resulted in the entire population of his conquered countries rising up against him.
I see an even more basic flaw in the French military attitude of that time which is highlighted by the word "pekin" that Sir Walter Scott mentions. Pekin was the word that the French soldiers used for anyone who was not military. In effect, anyone (regardless of country.. even French) was not equal in any way to a military person. It was a direct response to the eventual results of this attitude that animated and filled the Prussian, Brunswick, Russian, etc, armies with rage and a thirst for vengeance.
The peasants were, of course, non political but they certainly knew who was directly responsible for the death of loved ones and the destruction of their villages and farms. The general lack of respect for religion also played a role. While the French may have seen the local church as a handy building for their horses, this one habit alone burned in the minds of the local peasants who came to see N. as the embodiment of the anti-christ..
I think that France was actually very fortunate that Napoleon lost at Waterloo. If he had won; the Prussian, Russian, Austrians would have eventually finished the job and the entire French nation would have paid a heavy price. In 1815, N's time was over. The only question was how it would end not if it would end..