I agree, revenge isn't Walt's style. Every single murder he's committed has been a pragmatic murder. Maybe he would kill Hank if it would legally protect him and his family, but he wouldn't do it just because he's pissed.
I think Mike would disagree.
But Mike wasn't a revenge kill. Mike was a flying off the handle kill, an emotional outburst of the most violent kind. As brilliant & calculating as Walt is, he's also a slave to his emotional instability. Walt is a loose cannon. That's why Gus wanted him out of the picture, even more than he wanted Jesse out of it. As much of a loose cannon as Jesse is, Walt is atomic in comparison
You know who else is a loose cannon?..... H a n k. For all the talk about how in some way or another this situation could ruin Hank in the DEA (& it could even come to that) I truly expect that Hank couldn't give one single shit about that at all
From that conversation, it is clear that problem #1 is he will now have tunnel vision for Walt, which is certainly unsure territory to be treading like a bull moose, hence, Walt's comment, a purposeful intention, and even with as much as Hanks's learned about him... He's right. He has no idea who Walt is. That's problem #2. Problem #3 is that if Hank ever wants to come at Walt right. He can't go it alone, to be sure. Now's not the time to make it personal
Clearly, there's been some time passage in the forward, wherein Hank has yet to get him one way or the other. One thing is certain. That factor works in favor of Walt. When he's desperate & given time to plan. He comes up with some left field doozies.
I'm just sitting back & waiting to see which loose cannon gets off the last shot. The odds on favorite is undoubtedly Walt, but I'm an underdog man myself & that is without question, Jesse, who wouldn't surprise me at this point if he killed Walt in a murder/suicide, for all his self loathing