xAr4m1s

the order of the factors does not alter the product, is the same shit

I think that only when using the Mangekyo techniques does his eyesight wear out, so if he doesn't use the Kamui nothing should happen to him, it would just be like a normal Sharingan but much more powerful.

He could read or rather copy the entire scroll with his sharingan, since it is designed for normal ninjas without photographic memory, they never thought that an Uchiha could access the scroll of seals.

wasn't he dead?

The Duality of Man