I really haven't noticed much of a difference between running mohawk 94 and shell 92 octane in my Speed 6. Unfortunately with only a half dozen stations in town carrying 94 octane you have to make do with 92 from time to time. At our elevation there probably isn't a massive difference, even on a turbo car. The car doesn't ping or anything on 92 that I've seen so far.
The drivetrain durability has been a point of concern with me, but I haven't had any problems in the 6 months since I got the car so far. Time will tell I guess. As long as you aren't doing crazy clutch drop launches or anything I would think the driveline should hold up well.
Oh and I'd really recommend he get snow tires on it ASAP. Those bridgestones that come on it from the factory aren't even masquerading as an all season, they're a pure summer tire and should be treated as such.
Drag racing is for fast cars. Solo 2 is for fast drivers.