The Imperials didn't really do things logically or did they need to. The Clone Troopers were all a well oiled machine trained perfectly because of the clone aspect. After that they had to rely on conscription and it really seemed clear based on the choices made in most of the fiction (pre and post Disney) that they just relied on superior numbers and might.
Sure they are disposable fodder for shows/films so they can't actually put up a good fight against the good guys because that would mean the good guys should loose 50% of the time. And there could have been better fight sequences. But at the Jedi planet Gideon could have just nuked them from Orbit instead of even wasting time with troopers before blowing up the ships. That was why even the rebels were so effective because they used well trained (or at least experienced outlaws/smugglers) and actual tactics rather then brute force.
The empire was hugely incompetent. Was it by design so Palpatine could control better by having him and vader be "required"? Was it because they came from an era of relative peace and didn't have much knowledge? Were they just all boot licking idiots with millions more slaving away to take their place? Is it all just a story we all like to assign to much importance in order to find reasons to hate or like an aspect of that story?
The deathstar lives lost part was more of an easter egg to Clerk's then anything serious. But it does show the otherside, propaganda, and that the rebel alliance wasn't blood free. Which also helps to establish one of the New Republic's weakness and how the first order could take over. They wanted to shy away from rule through might or large scale conflicts.