NYCRider, first, since the bike is not brand new, I would diffently want to look at the bike in person and then test ride it before purchase unless you're feel real lucky. Then you want to look at records or any paperwork kept, pink slip, registration, bill of sale, any warrantee work done, any work done period, service records, parts purchased etc.
Next, take a look at the oil. Dip your finger in it to see if its clean, and smell your finger, (no wise cracks from the balcony please), for any signs of burnt oil and then rub your fingers for any signs of metal particles in the oil.
Take a pin light or small flashlight and look under the bike, in the bike, anywhere you can see to check for loose or broken wires, cables, signs of leaking oil, fluids, gaskets, bent or worn suspension parts or bushings, leaking shocks, etc. You should be able to tell alot about the bike if its clean and kept in good working order just by looking at it.
Listen for any abnormal sounds when starting the bike and when its running, like the tic mentioned. Check all the controls, levers, switches, etc, to make sure all the lights, turn signals, brake lights, ease of throttle, etc. are working.
Look at the brake rotors to make sure their smooth and not grooved or worn. And of course look at the tires and how they've worn to make sure even wear has occured. You might see some flat wearing on the center of the rear tire which is normal.
You can do a background check on the VIN number ahead of time to make sure its all legal like and other than that, maybe someone else has some ideas. From your description above already sounds like a nice bike. Good luck and let us know how you did. PM. <><