I would never use carefresh with an animal that urinates as much as a rabbit. That stuff starts out really dusty and absorbs a little too well, leaving soggy bedding and chances for mold. Petsmart uses the stuff for guinea pigs and rats, even though they shouldn't, and the poor dears suffer.

As for leafy tops, I use beet and radish tops from the store and wash REALLY well. No bad effects thus far. And you should leave water on the greens since it's a major source of water for them.
Just keep trying your bun on different food items to see what they like. Some can be really picky.