My point in #1 was not that theft or murder are inherently not-anarchist (which is what I was getting at in point #2)*, but rather that if there were an assembly with 100 people present, and 51 of those decided that the best course of action was to murder and take the property from the other 49 people, I don't see that as a decision that matches up with anarchist praxis.
There could certainly be extenuating circumstances (51 anarchists show up along with 23 cops, 10 klansmen, 5 CEO's, and Mitt Romney...), but generally speaking I think that if a decision can only be defended as being made by majority rule it is not a decision being made by a group that can lay claim to the title "anarchist," if that is the only reason they are choosing to do so (I recall an episode I happened to see of the show VIP, starring Pamela Anderson, where her spy team thwarts an anarchist plot to destroy technology in defense of the earth and the one clear explanation of anarchy is, "I'm an anarchist, I can do what I want," which is true, but is not complete somehow...)
I also think that, so far as I understand functional anarchist assemblies, they are not a place for that decision to be made, but rather a place where a group would put forth their analysis of why this action was appropriate, and then seek allies in carrying it forward, as opposed to a meeting, where people decide what to do or not do. This bit wasn't what I was getting at, as I think the term 'assembly" means lots of things to lots of people (perhaps like "anarchist"), but it does illustrate another problem with the assumptions in this question.
*edited because math... and in my initial editing I made some things unclear that should've been clarifying. Also a broke-ass keyboard that is getting more broke daily.
*A further clarification- I just re-read this comment, and I wrote it as if point 2 was arguing murder and theft were un anarchistic, what I meant to say was that it was not my point in number one and my goal with number two was to in fact refute that concept. Of course anarchists can murder and steal, we always have.