Pain & pleasure are both devised of our own perceptions. Without our senses we would never be able to determine the difference between the two. Even with senses intact what could be considered pain or pleasure may variate greatly between two individuals. In example I may enjoy a certain food while you may find it repulsive.
You are asking two questions at once here.
The concepts of pain & pleasure and good & evil are two completely different things.
This is a great question :) My very young son came up with a similar question and I found it most difficult to answer. You would have to input of information, nothing to conflict, and maybe too no awareness of your existence or very very different then us with senses can even imagine. Too bad we can't ask someone who has no senses :P Ask this question in another life and you may possibly yield better results or google it...lol
That question is way too deep for EP. Stick with stuff like, "Do you use deodorant on your ***?"