Danzo exists on a continuum somewhere between greedy and will of fire. However, he is much closer to greedy than will of fire.
Somethings he did where purely selfish, like not aiding in the Pain invasion and letting tens of thousands die so he could assume control of the debris. You have to be pretty arrogant to think you being in charge is worth your village's destruction.
He is hypocrite who preaches about need to sacrifice, but does not do so himself. His self-destruction was preplanned, not a final act of heroism. Also, what would have happened if he had died of natural causes in the Leaf?
one of the reasons, he committed flipping genocide was to steal Sharigan for himself.
On that topic, why didn't he just arrest the leaders? That's how sane people deal with a coup. genocide is never a viable option.
However, at least some of his motivation was to defend the leaf.
It's implied he hated himself for his cowardice. So that's something I guess.
To his credit, Danzo did do one of the greatest services to this manga. He showed that not every single leaf-nin was always a hero. he added some moral complexity to the story.