Can you be blind in one eye but still have cranial nerve function in it, with eyeball moving as it used to?

Yes: If you are totally blind in one eye it is generally for one of two reasons: an optic nerve problem or a total, inoperable retinal detachment. Neither one of these would have any impact on the cranial nerves that are responsible for eye movement. These are cranial nerves 3, 4 and 6 and they would continue to innervate your extraocular muscles and permit the normal movement of your eye.

Blindness: Blindness in the eye can be unrelated to the cranial nerves that move the eyes, so these nerves can be normal even if the eye is blind.