Despite all the factors:No he doesn't because there's other ways to hurt someone besides cutting them. Just because Mihawk wouldn't be able to cut him doesn't = him not being able to be hurt it just means his skin won't break, Mihawk's slashes could hurt him they just wouldn't break his skin and cut him they would deal impact damage though as the force hits him. Think of Kaidou as Luke Cage and it's easier to understand that he can be hurt and beaten and still remain un cut. All Mihawk not being able to cut him would mean is that no one would be able to cut him, which no one is arguing because that is a fact, if Mihawk can't cut him nobody can cut him but that doesn't mean that nobody can hurt him.
1) High level of Haki and swordsmanship.
2) #1 Great Sword.
... just what's with Kaidou's skin? And yet he's probably wouldn't need to use Armament Haki for this matter... I think Oda no matter how genius in plotting he is, he's gonna fail in bringing Kaidou down.