Well, I agree that Walt bears a great deal of responsibility for a lot of stuff that happened, but I'm apprehensive about putting it all there. Almost everybody made decisions that had consequences, and Walt is only responsible for them indirectly.
For example; Jane's death, which wasn't Walt's fault, was what sent Q into a downward spiral emotionally, no question. Walt could have prevented that, but he didn't. However, it was entirely Q's decision to return to work. You can't blame him for wanting to get on with his life, but it was his decision that caused that plane crash.
Another example, I don't believe that Hank's death is really Walt's fault at all. He definitely set in motion the events that led to it, but so many other people making poor decisions contributed to the escalation, something Walt was trying desperately to prevent. He was trying to make things right with both Hank and Jesse the entire season and was opening doors for both of them left and right. He even called off Jack and his thugs and gave himself up, and after that went south he tried to buy Hank's life. He was willing to part with his entire fortune if it saved Hank's life. However! However I will admit that this was the end result of most of Walt's crimes. It's kind of a conundrum, really. Did he cause Hank's death? I'm gonna say probably, but it wasn't just him.
So, does a lot of blame deserve to go to Walt? Hell, even the majority of the blame? I say yes. Killing Mike when he didn't have to, I think, was probably the most heinous, unforgivable thing he did on that show. The guys in prison I don't really care about so much, because you could kinda tell that they were all headed for the graveyard from the word go and also because we didn't know them as well as we knew Mike. But does he deserve ALL the blame for everything that happened? Absolutely not. Hank, Jesse, Skyler and Gus all bear a great deal of responsibility as well, that's all I'm saying. I hope I'm not coming across as a know-it-all dick, because that's not how I'm intending this to sound. I just want to explain why I think what I think.