FYI, everything being discussed here is actually part of the original question:
"Is Varsuuvius Lawful, Chaotic or True Neutral?"
Consider that motivation is the exact same in both cases, and you're aware of alignment in both cases. See these two cases:
A) This guy is a jerk, he has wronged me moderately (I'm not aware of anything else he did), and I could actually use his nice equipment for my (Good) purposes, and I know he's ultra-Evil --> I'll kill him and take his stuff
B) This guy is a jerk, he has wronged me moderately (I'm not aware of anything else he did), and I could actually use his nice equipment for my purposes, and I know he's Good --> I'll kill him and take his stuff
Equally Evil, or is the latter worse?
The first act helps the cause of Good and weakens Evil, while the second does the opposite.
See for example how Eugene blamed Roy for letting a bastion of Good be overrun by Xykon... Had it been, say, Greysky City being invaded/destroyed, I'm pretty sure that would've been quite a bit better from a "greater Good" point of view. In other words, I think those things (whether or not your actions are contributing to the greater Good, even if it's only a side effect, as long as you're aware you're doing it) do matter in the Stickverse.