I am going to say that you do not have a blown head gasket. As long as I have been around these sites and these cars I have yet to see any single confirmed case of a bad head gasket. Not saying it isn't possible, but highly unlikely.

I would bet your coolant loss is either your LIM gaskets or the water pump. With the description you give with liquid being slung off the belt I am leaning towards water pump. The weep hole is on the bottom side of the pump and is hidden by the pulley, basically no way you can see it without removing the belt and the pulley.

When the seals begin to fail water gets by them and drains out the weep hole, sometimes they only leak when cold, sometimes only when hot. A slow drip could evaporate when the engine is hot before it gets a chance to ride the belt enough to sling around.

Also make sure you check your PS fluid level, just in case that is the fluid on the belt. Any oil on the belt will be fairly easy to detect though, just look at the belt with the engine off. Water / coolant will evaporate off whereas oil will stay.

I have had a hairline crack in the same spot on 2 GM radiators. It was in the top plastic section on the drivers side. Coolant would seep out only when radiator was full and hot. It would come out slowly, mix with the dirt and engine grime, and look just like engine oil at the bottom of the engine and frame. These cracks were not on my Bonny, but on a Bravada and a S10, but my lesson learned was that slow leaking coolant, when hot and from a high location, ends up at the bottom of the engine and frame and looks just like motor oil.