Finally fixed the exhaust gasket leak. Ended up taking it to a local shop I trust, since my indy does not have shop space at the moment. I provided the updated Volvo 5 layer gasket, along with stainless steel studs, washers, and nuts for a Focus RS MK2.
They found three broken studs and got through them with little drama. 5 hours of labor later (and a new rear O2 as well due to fraying wiring), success! I was anxious at first after paying and jumping in to drive home, but I found several things got fixed as a result of replacing the gasket and hardware:
1.) Obviously, no longer a screech at startup and no exhaust smell in cabin.
2.) High Idle takes less time due to engine warming up slightly quicker.
3.) Engine gets to full temperature sooner.
4.) More low end torque, due to all the exhaust actually spooling the turbo now.
5.) Due to more low end torque, better 1st and 2nd gear engagement for starting from a stop.
6.) Whirring noise that only occurred in 2nd gear is gone (my guess is that again, it was leaking exhaust and spooling for boost limit from ECU).
All they did was replace that gasket, hardware, and O2 sensor. If you're reading this, and your car has this issue, do it as soon as you can. I'm really enjoying the car again and now my neighbors don't hate me
Sourced and replaced the hood support strut as well, STABILUS part number below.