Well, yes they vent through the PCV but the vapors are caught by the catch can (if you have one). If not, they're either burnt or accumulated and then deposited in the manifold or another part of the engine.
Where are the turbos located? Are you able to spin the blade by hand? See if it has any play in any axis. Forced induction is a totally different animal. Since even a small problem can equal a huge discrepancy between how much air the ECU expects vs how much it's getting.
Also check the MAF...
Undercoating will do nothing for galvanic corrosion. Unless you can get the coating in between the steel and aluminum, you can't prevent dissimilar metals from corroding.
I'm glad they're giving you a new hood because even if sanded and repainted, that area will always corrode. No way to...
Was the hood wet when you took pics? Because there's quite a few paint bubbles I see (besides the edge area) which look like overspray.
The bubble on the edge has been happening since mid 2000s. Ford still hasn't gotten their shit together.
I'd watch this and make up your mind. Honestly the Walmart's Everstart Maxx and Autozone's Duralast Gold would be my choice, but the others in the vid aren't too bad either.
If you want to save some weight, you can look into lithium battery, but be prepared to spend a few hundred.
Fixing swirl marks is one thing, having to have a shop fix larger scratches is totally unacceptable for a new car. You're being forced to remove parts of the already thin clear coat, leaving you with less material to work with in the future.
I wouldn't bring this back to their body shop. Best case scenario, they decline the work. Worst case scenario, they just put some shitty putty there and touch it up and cause more damage in the process.
Did you have the grinding noise before you put the MGW in? It sounds like it only happened after you installed the aftermarket shifter. If that's the case, they're 100% in the right to deny the warranty because it sounds like the shifter caused it.
It depends on what failed on the car. If it overheated and siezed, then maybe they messed up the radiator or fluid. If you damaged something internally in the engine, you'll have a hard time proving the dealership did it.
Your best bet is to test the MAF plug with a multimeter. Maybe your voltage is too high or too low for the MAF to operate properly.
The MAF sensor works by heating up a filament and then detecting the temperature change via measuring the resistance of the filament.
If the voltage isn't stable...