danzo is not a teamplayer, even at the kage meating he was using shisui's eye to manipulate his way to power, a very selfish act if you think about it. also, I don't think he has the background for the job, the other kage's just don't trust him, that was also proven at the meating.
could he have survived the transport technique, perhaps if inzanagi was already active, but that's waisting time. and I'm not sure if shisui's eye in the hands of danzo would do the alliance much good, if he uses it to save the alliance (like say using it on edo madara) I get the feeling that someone with danzo's personality would have sectretly implanted other commands aswell that would benefit him and konoha after the war ends, and it would just start another war.
so in terms of leadership, in my eye's he's no good for the alliance
in terms of the fight against edo madara, he would have been usefull to have around but not as a leader, a soldier yeah, sure, I would have him, if he obey'd commands