My understanding of it when I read the books was the spice gives them similar prescience abilities to Paul. Effectively allowing them to see what’s ahead and navigate before it’s an issue. Especially because they’re flying faster than light so they can’t rely on their eyes as they’d crash into something by the time they actually see it.
I have a hazy memory of the book explaining they were once humans addicted to spice, so presumably they have some controls.
Kirk was always in the chat, he’s now just more open with kinks