I agree with point 1 and 2 comparing the Death Eaters with an aristocracy, a ruling class confined only to themselves, Lucius Malfoy being the unparalleled example.
Remember how Lucius Malfoy always sneereingly looks down on the Weasleys; a working class family with lots of dirty kids and always at the brink of destitution, who also condescend to associate with muggles?
Remember the absolute power one has over the house-elves?
I think the Death Eaters want to substantiate that absolute power, including the right to use dark arts as a means to demonstrate their superiority. I think it is this allure of absolute power and unrestrained wizarding that attract followers to Lord Voldemort.
Also because I got the impression that being a pure blood family with monetary and political power was a dying tradition in the wizarding world; most wizarding families were “watered down” because of the occasional muggle married into the family. I guess the ultimate goal of these “aristocratic” wizards is to restrict the permission to do magic to pure-bloods only, and since the majority of the wizards have a “muddled” heritage, the pure-blood fraction of the wizarding world would have absolute power.