First of all just look at it, does it look like it has been treated well? Do you like how it looks? It is something you will have for a long time so be sure you like it!

I just looked a the pictures, it is a foam/fiberglass laminate so it could be delaminated, but I don't think Nacras have that problem very often. I would press on that area with the peeling paint and see if it is soft, that could have been caused by water leaking through the hull. If it is solid, no big deal about the paint but if it is soft, run away!
Ask him if it takes on any water? I would say up to a gallon in each hull is not that big of deal, more than that, something is wrong. It is pretty scratched up at the front, ask him what they are from? If he knows it is a good sign but if he has no clue he probabay didn;t care about the boat to much.

Check the rudders and make sure they they are not chipped and beaten up. Also check the rudder assembly, make sure that nothing is bent, I would have him put the rudders together. If you have time and the space, have him set the boat up, with two of you it would only take about 1 hour to set it up and take it down and then you could make sure that everything was there.

The sails look good but look for anything wrong with them, that can get expensive very fast!

That is about all I have to say, it looks pretty nice, I bet it is fast!