Could be condensation build up inside the valve cover would cause a small spot. Is it water that is leaking or is it oil? The timing covers are kinda hard to keep from leaking oil, the biggest diffrence there is what was used as a gasket sealer. The tell all test i do for a blown head is i leave the radiator cap off and start the engine, if it shoots out the top like a fountain thats a blown head. It is normal for it to flow over very gently as the water pump is turning so it pushes the water, that usually happens when the radiator is plum full too.
If you have a compresion tester cheak for leak down across all four cylinders.
For the temp spike when was the last time you changed the t-stat? Should have done that when you flushed and replaced the coolant, which i do begging of summer and before the first freeze. I usually run a 192 t-stat. When i flush the system i run water through the rad seperate, through the block seperate, and also throughte the heater core seperate, that is a step alot of people dont do and i have the best heater out of all my buddies.
Be very careful about re-torquing the head bolts, they shouldn't come loose any way, but over torquing can be a bad thing.