That wasn't the reason at all. He spammed MS because it laid a lot of pressure on Danzo, and forced him to use up Izanagi quickly. But as we've seen, even well-aimed shuriken can force him to start an Izanagi. And it's not like Danzo can pause his Izanagi... once he's used an eye, it will just continue until the eye is sealed off.
It's a matter of who can outlast the other. Since this War Arc Kakashi, his reserves are pretty big and he can make his chakra last quite a long time since he's not using Kamui.
And he's not pulling out Baku either. Baku was used as part of a strategy to break open his Susano'o... that's always only when large summons are used in battle - either against large constructs or large opponents. The Futons can be copied if used against him, in a similar way he did against Kisame, and technically Kakashi does have Katon, though what jutsu we'll never know.
He needed Susanoo to protect from Danzo's sneak attacks with Izanagi, he needed it for Baku, and he had to pressure Danzo because otherwise Izanagi would be drawn out longer than Sasuke could fight.
-Kakashi's reserves are not large. Right before making a single clone he said he was worried about his chakra reserves. He's obviously not going to come close to outlasting someone with Hashirama's cells and Izanagi.
-Baku was used because he needed it. Nothing more, nothing less. If he needs it here, he will use it.
And sure, he can probably copy Fuuton, that is if he sees the hand signs. If Danzo uses Izanagi to spawn out of Kakashi's LoS and then attack with a Fuuton he won't be able to copy it, all he'll be able to do is evade. Danzo was able to grab Sasuke's neck and apply the curse mark before Sasuke could cut him. This was all without his Sharingan which dramatically increases CQC ability to precognition. Kakashi isn't going to go through this battle without being tagged by Danzo, and when he does the Curse Mark ends him as he has no way to break out of it.
@bold bro, Kakashi has copied several jutsu and the databook lists him for all elements for what it's worth.
OP: Probs Danzo.
Lmao yet he hasn't used one on panel, so we have no idea which jutsu he knows so there is no point trying to use it in an argument.
Raition dogs should work.
For what? I hope you know Fuuton beats Raiton. So Raiton Dogs are almost useless here. Especially due to Izanagi.