I'm of the mind that anyone who willingly gets drunk is as responsible for any and all behavior they do while drunk as if they were stone cold sober. Seriously, personal responsibility from drinkers has been a joke as people use it as an excuse for avoiding responsibility for their actions, and for some reason society has adapted to that mindset as well. But it really needs to cease. If someone chooses to weaken their own judgement, they they need to deal with the consequences of that action. Killing someone while drinking and driving should be as severe, if not more so then doing it while sober. More so since they willingly chose to be stupid and weaken their judgement and make themselves a danger and break the law about not drinking and driving on top of the whole killing someone behind the wheel bit.
With regards to being black-out drunk, nothing changes. Unless you have someone actively drugging you against your will or without your knowledge(a different issue of them deciding you should be out of your right mindset, something that should be a heavy crime and be viewed in any decision you make after that point), any decisions you make while drunk that bad are still yours to bear the consequences of. You go out and punch someone in the face while drunk, it is the same to that person as if you did it while sober. Your drunkeness level doesn't make the damage less because you might not have decided to do it while sober, so why treat it as such? The damage is still done. Doesn't matter the degree of being drunk, the punch is the punch is the punch so why would anyone see the same action in a different light based off a previous decision the perpetrator did before that point?
with regard to sex, again, if the person choose and willing got themselves drunk, they are responsible for their own actions including agreement to sleep with other probably likewise drunken people (general bar setting is what I am seeing this sort of thing at). About the only time this does change is black-out drunk because, well, hard to give consent while unconscious and all that. But with regard to especially minor alcohol involved before making that decision, person who is drinking is responsible for their decisions before and after.