And it goes without saying that we're just here to help you & your snake have the best experience....so if you need clarification of anything, just ask.
(We were all new snake-keepers at one time, lol...)
And yes, feeders should be roughly the same diameter as the thickest part of a snake's (un-fed) body.
Snakes do defecate, that's normal, not a "rough night"...only for us, doing clean-up.I suspect your snake feels better now.
Feeders: as far as rats or mice, when their eyes are still closed ("pinkies" or "fuzzies") they do not bite back. When their eyes are
open (from "hoppers" on up) they do bite, just so you know.