How long does it take for a C&R Rainbow returned the proper way,
To start taking the fly again,
If they were caught on say a black Buzzer will they be wary of them next time,
i suppose they dont have the ability to think like that.

I think they return feeding a lot quicker tan you think, a lot of people have stories about getting snapped by a fish and then catching it again soon after. Also I'm not sure if the become more wary of black buzzers if they are caught on one. I think if they see another black buzzer they'll take it, as their thoughts are only on surviving. I remember catching a ghost carp around 5lb on floating bread, I then saw it half an hour later taking bread off the top.

I'ld say it depends on the time it took to bring it in. The longer it takes the longer it is going to rest before feeding again but I'ld say you're talking under an hour. I have the experience of a rainbow that I released after a very quick fight then about 45 minutes later I went by the same place, cast to a rise and caught the same fish on the same fly pattern. I knew it was the same fish from cormorant scars on it's side and for all I know it had been feeding for a while.