No worries dude.
1. I go with what I have been told about fitting these to an R33, I havent done it myself so I cant really guarantee that. I would suggest for piece of mind tha you ask a few people that are in the game or have experience with it.
2. I bought them second hand, like new with about 3000Kms, just after I bought the car about a year ago, since then they have done 9000kms or so.
3. They are in Top condition, no rattles, no noises, nothing.
4/5. The reason why Im selling is the same as why I have only one rear. I had an accident and one of the rears is f**ked, the other one is fine.