The driveshaft that continues to turn in nuetral is normal. It's the "thickness" of the gear oil in the trans making it turn. There's no real torque being applied to the driveshaft and won't take much resistance to stop it. The other problems sounds like the pressure plate broke, but I've never heard of that happening before. If you replace the clutch, replace it all as a kit so you won't need to pull the trans for a long time. Lube the throw out bearing surface so it slides smoothly and lube the pilot bushing so it doesn't wear out prematurely.
Good luck,
Scott
