Ummm . . . . Talking, writing, etc is called communication. If you use words that your listener or reader doesn't understand, you're not communicating, just making noises or marks on paper or screen.
To that end, foreskin is universally understood. It really isn't shaft skin. Although it appears the same on the outside and there is no line of demarcation, the foreskin is different than the foreskin in sturcture and in skin type on it's inner surfaces. The inner foreskin is mucosal skin. The foreskin also has unique anatomical structures such as the frenar band or preputial sphincter. Not differentiating between the foreskin and shaft skin would be like trying to not differentiate between cheek skin and eyelids. There is a difference.
Prepuce is correct but if you say prepuce to some people, you will get a blank stare from them. Penile/penis skin does not accurately describe the foreskin/prepuce.
I occasionally use prepuce selectively but I think foreskin is more universally understood.
Nay, we've had enough trouble with "intact." Are you trying to be a trouble-maker?

Frank