Thermal compound application was perfect! The temps (according to CoreTemp) haven't exceeded 39 C, and idle around 33 C. I think this is perfectly acceptable, esp with the stock cooler. Checking BIOS, it says 30.0 C.
I think the hang is just due to lack of temp in the cores at startup and once they get up to temp after a few seconds the fan kicks in. This is the only reasonable explanation I can think of. Does this sound right? It still freaks me out a bit, but I'll live with it!