This comes from a bookmark folder entitled "Stuff to Blog" which I obviously haven't done any emptying of in awhile.
Do yourself a favor and read the whole, short thing.
The gist on the one hand is that neither the Empire doesn't make political decisions, and this is true.
The Empire ruled through fear . . . the political consequences that we might hear discussed in the Clone Wars era become increasingly irrelevant to the power structure of the Empire during the time between III and IV. It went from an ostensible (and unworkable) democracy to a society of lords and peasants under their heels within a generation. And yet the Rebellion was small and struggling. In short, this technique of rule was largely working. The people were probably well fed and well entertained . . . bread and circuses, much as we see today . . . and kept uninformed and/or propagandized.
And yet, the people also had to be kept fearful, both of the Rebellion and of the Empire's might against enemies within, which could've been quite the juggling act. At least until you get the Death Star, but at that point any veneer of respectability is wiped away.
As for the points about the Rebellion's techniques, I think it likely that a number of small insurgency-style events occurred, but that we see the big ones because, well, they're the more interesting. But it is troubling that the Rebellion was on the run and in such dire straits during ESB, for instance . . . after Alderaan and their victory over the first Death Star, you'd think they'd have had safe haven everywhere. Presumably the Emperor really ramped up basic military action against suspected sympathizers and such after the loss.
In any case, there is a great deal to ponder here, and I have merely scratched the surface. The rest I leave to you.