First, I would remove the drive belts and start the engine for a short period. If the squeak is still there then you know it is not a belt driven accessory. Spin each pulley by hand and feel for roughness while listening for noise. A tech I work with has the same engine in his Bonneville with a squeaky (bird chirp) noise. His turned out to be a bad belt tensioner. I have seen several of these go bad, the bad thing is that they only come as the complete $100+ assembly from GM. The spring seems to lose tension and cause the squeak noise.
Don't forget, every 3 years or 30,000 miles you need to check and top off the supercharger oil.
For the coolant smell, I recommend starting with a coolant pressure test to verify if you have a small external leak that could be evaporating or burning off and causing the odor.