About Luffy's fist going through Kaido's face:
I think people misunderstand what's happening here. Luffy doesn's punch through Kaido, but he punches so hard that Kaido's face stretches along with the fist (which can happen because of Awakening I presume)
The same happens with Kaido's eyes; Luffy doesnt go through his eyes, but he stretches them over his hand like a rubber glove (again, though being Awakened I guess). I think it's hard to see because of the black/white nature of manga.
(I could be wrong of course, but this seems like the most logical explanation)
Edit: The some logic applies when Luffy uses his Gum Gum Balloon inside of Kaido. Kaido himself is even surprised by this and states: "Curses!! What's wrong with me?! My body isn't made of rubber!!"