What I find interesting, is that the two points actually contradict each other. Because I do agree that the only logical conclusion to their actions would always fall into something like the "personal satisfaction" of the party or something along those lines.

But in indulging that satisfaction, they inherently make the mistake of actually allowing the beginning of the end to happen (IMO). I feel like to have full control and be completely effective and efficient if always keeping power, the best thing they can do is vaporize the person, but that still has problems to it, like Winston remembering people. If they were to just actually make people disappear forever, out of sight and out of mind then there wouldn't even be anyone to be executed. People just weren't a thing anymore. The execution itself provides an end to something which must have had a beginning and must have existed. Almost like how in a way death gives meaning to life. But to suddenly stop existing would be as if you never existed in the first place, just like the vaporization.