I feel as though youre showing the symptoms of a couple of really bad lower intake manifold gaskets and a stuck/sticking PCV valve.
It's very common at around 80k miles for the LIM gaskets to leak, this causes coolant to go both into the intake ports, (why it smells like coolant from the exhaust) and down your valley pan. Also can be why your cooling system is getting excess pressure if this happens under boost. It will also show signs of coolant in your oil since coolant will mix in the valley. Which is why if left alone, will only get worse and start giving you these problems
If they are bad enough, they will give you all of the symptoms of a blown head gasket without actually being the head gasket )provided you can do a compression / leak down test first to confirm this
Don't jump the gun and just start tearing down the engine, first take your blower and LIM off since they are going to need to be changed reguardless and see if the rubber is seperating from the plastic. It's fairly easey, and can be done in 45 mins to an hour with basic tools.
Word of advise, replace the LIM gaskets with a pair of aluminum replacements VIA GM directly, or ZZPerformance.com or any other similar sites, they are a better quality, and almost never go bad even with running higher boost levels and Be sure to be carefull when replacing the heater core elbow as they always tend to break off/fall apart
Provided that this car is completely stock, the odds are very slim that she blew a head gasket even with overheating the engine.
Also while im thinking about it, check around the ports of the LIM for pitting as the LIM gaskets if left to leak can allow coolant to cause this, and inspect the coolant "o" rings for signs of leaking as well
