All your assumptions are correct on the timing, with the lone exception that the 60' measurement isn't always insanely accurate from event to event. My STi pulled the fastest 60' time of the entire event at Wendover three years ago, and there was an SM Evo there. It was a 1.67 or something incredible like that. It was my first launch of the event on bone cold tires. It was a red-line clutch dumper (with throttle flutter to maintain boost) and the theory was that the cold tires helped since they spun a good bit more than they otherwise did as more rubber got put down and everything was softer and that kept the car on boost better. That was everyone else's theory, my theory was that I'm just a bad-ass to 60'. It's after that when I got all to crap.
As for the mental part, well, it's there, but *I* have never found it hard to tune out the other driver. The courses are always setup such that you'll be able to see your competitor at some point and gauge well who is ahead during a run, but I never notice it. And having a Subaru pull you like that is just good practice for the Challenge since it's possible you could face a car with a slower dial-in than you and thus will be allowed to leave earlier.
--Donnie