He was under the impression that she would be fine. It was stupid of him (and yeah lacked forethought) but I think its a bit extreme to say he was being a selfish asshole. Mostly just ignorant of the fact that what he did was extremely irresponsible.
Honestly, I surprised you weren't more affected by the sheer stupidity of Walter letting Jesse's girlfriend choke to death on her own vomit. (I say stupid assuming he wanted what was best for Jesse, which is pretty obviously the case.)
Walter and Jesse are probably the most human characters I've seen in a show. Mainly because they both do infuriatingly stupid fucking shit. (this of course not being the only way to make very human-like characters)
If they were real people, I would pity both, and feel very ashamed for them. But I wouldn't hate them or be irritated with them, they are unfortunate products of their environment.
Also, I'm pretty sure there are few people to ever live who wouldn't shit their pants or at least come close to the prospect of full on torture. Pretty sure Gus would react much the same way if the roles were reversed. Felt bad for the guy he killed.
Oh and jamie, I think there is actually a pretty good opportunity to do a good redemption ending. In fact, a 'moral pit man' ending would bore me since it'd get old just watching Walter just sink and sink and sink. (though I imagine the way he sinks might be still interesting) Because it seems like we've got our fill of that. But that is just me.
Also, I would like to see Hank back on his feet because watching him be miserable and make his wife miserable its... eh...
Overall though still think this is basically the best non-episodic-natured show on tv. Best episodic-natured one for me probably being House.