Alcohol, not being sentient, can’t seriously be considered evil or blameworthy in the way many people (not including me) think some humans or other sentient beings can be. It is probably more fruitful to forget about blame and think instead in terms of causes and possible solutions. If the person drinks and succeeds in becoming more violent as a result, then alcohol is a cause. But attempting to deprive this individual of alcohol would probably not achieve much in the way of solving the problems. The immediate causes of the person’s choosing to drink would be his own mental states: his beliefs, desires, hopes, fears and so on. Some of the causes of those might be internal the individual: an imbalance of chemicals in the brain, or a lack of certain neural structures, perhaps. And some will lie in the individual’s social environment. A detailed case study would be required to get the full story, and to determine what, if anything, could be done to make matters better.

there is some potentially relevant empirical material here: http://www.faculty.ucr.edu/~eschwitz/ in the section: The Relationship Between Moral Reflection and Moral Behavior:

I am far from convinced that a particularly large number of atheists think that other atheists "ought" to be a humanist, or at least care about animal rights, environmental protection, left-wing politics, and so on. Do you have any evidence for this idea? I am also puzzled by the suggestion of a naturalistic fallacy. You seem to be attributing to this possibly imaginary large number of atheists some kind of argument that they are supposed to put forward. But you do not say what it is. There are many religions and many religious people and many different sacred and textual norms saying or implying completely different things about animal rights etc., many inconsistent with others. And these are followed in many different ways by different people. Atheists do not tend to follow sacred texts. But there are large numbers of texts about about animal rights, environmental protection, left-wing politics, and so on that have nothing whatever to do with religion.

I would say: it is ethical to kill someone in self defence as long as their life is not more valuable than yours. In the unlikely event that the person attacking you is a terrific assset to the universe and you are not, then you must let them kill you rather than kill them.

I am not sure who argues that the act of dealing arms is not morally wrong. It looks like a bad argument to me. If you sell someone arms, then you have no guarantee that they won't use them to kill people illegitimately. In fact, often, that is just what happens. So it is imoral to deal arms. A parallel argument applies to drug dealing.

I think that that is a very good rule of thumb. Humans often react to violence by retaliating. Hence many of the absurd feuds and wars that go on. Of course, one can think up exceptions. But they are rare.

I would have thought that our responsibility is to use the technologies responsibly and safely. It is not as if we are incapable of this.

That's a lot of difficult questions! First: I think we can do wrongto people who don't yet exist. It seems unfair to be less respectful ofsomeone who will be born in, say, 2020 than someone who was born in,say, 1995. Second: it is not obvious that your second question makesmuch sense. You can't do wrong to a being who doesn't exist, never hasexisted and never will exist, simply because there are no such beings!A future being isn't yet around to be harmed, but will be later. But non-existent beings aren't there to be harmed. You go on toconsider a conditional: 'if ... it isn't wrong to cause them never toexist ...' where 'them' is supposed to refer to future people. But ifwe cause there to be no future people then 'them' doesn't refer andthere is no issue about harming them. Still one might wantto argue that we have a duty not to make the planet uninhabitablebecause we have a duty to our species. I am not sure how to justifythat, but the thought seems to have some intuitive appeal.