I like leading really small, like ~3, on the river. Some 2pair or sets call you and 8x might jam over you.
x/r turn is fine too.

Definitely x/r turn.

I think I do prefer x/raise turn, although he won't have many worst hands to call with. I don't like the idea of just calling to let him get there on the river... + even if he doesn't have the FD a club on river will kill your action.

So yeah, I prefer x/raising turn, sets and combo draws will call you off sometimes.