1) When I was tightening down the cassette lock ring, it felt like it was clicking as I tightened it. I used my experience with cars to not break anything and I just made it pretty damn tight and ignored the clicking. It looked like there was some ridges in the casting where the lockring was up against the tallest gear on the cassette. Some clarifications: I had the tool seated in the lock ring and held in with a spare quick release mechanism. I was using a foot long 1" cast wrench so there's no way my tools were making the clicking.
2) I had a complete spare drivetrain with a 12-27 cassette and a 38T inner chain ring. I reused the big chain ring from my 11-23 / 39-53 drivetrain. Everything else was already worn into itself. Said another way, I had two chains, two inner chain rings, and two cassettes. Is it likely that the big chain ring will accelerate the wearing on whichever of my drivetrains is newer?
Other than that everything went smoothly. I really was missing the short ratios. I love being able to blast away from stoplights and I believe that I was risking the potential of injuries with that 39-23 ratio. 38-27 should be more realistic for my strength.