S1 - could've called cops on the dude he killed. Has remorse killing him, but this is where I felt he became heisenberg. To continue with making meth and not dying with self-guilt he was already a hardened asshole and it set the tone for everything else to follow. (Good on Gilligan to get him to "kill" someone so early in the series).
The man was going to kill him as soon as he took the handcuffs off.
S2 - Doesn't save her, has no regrets. Asshole.
She was going to either get both her and Jesse killed through Od-ing, or would have blackmailed Walt when she ran out of drug money. She turned out to be a massive bitch and Walt showed remorse when it happened and after during a few scenes in the meth lab
S3 - Eliminates the two people for Jesse, shoots them in cold fucking blood. Gale death not withstanding.
he kills two people that murdered a child in cold blood, and does so to save Jesse's life when he doesn't have time to stop Jesse from stupidly going to shoot them
S4 - Kills Gus, who wanted to kill him because he knew how unhinged and dangerous Walt already was (tricking jesse to kill Gale). Both men were justified to kill each other, if we are to take this angle. Gus made the decision to kill Walt when Walt saved Jesse's life, how much of season 4 did you watch?
Walt didn't 'trick' Jesse into killing Gale, he didn't intend to get stopped outside his house by Mike, after all
S5 - After Gus, he has earned his "kingpin" status as he believes. Has Skylar and Jesse by the balls and emotionally manipulates them.
Skylar has been emotionally manipulating Walt for some time as well, it's only after she gave him the 'I'll be whatever kind of partner you want' speech that he finally gave up on her and keeping the family together. He was ok with the divorce until she refused to let him see his children.
Your last sentence, and the death of the girl in season 2 are the only ones with some merit, the rest are extremely flawed[/B]