Pardon the tangent:
1) What's your lifetime Wh/mi?
Approx. 315 wh/mi. I say "approximately" because I lost my lifetime stats when I upgraded my MCU last year, but I don't suspect it has changed much or at all since then.
2) How quickly do you tend to accelerate and how often do you gun it?
I drive... assertively? Not super fast, not super slow, but I'l get on it every now and then and am not averse to carrying speed through corners. I do live in the foothills/mountains and my usual commute is about 50% fairly rough 2-lane mountain/farm roads and 50% smooth flat freeway.
3) Is the tire wear on the rears even from tire shoulder to tire shoulder?
Yes, they've always worn pretty evenly, at least as even as others report given the fixed negative camber from the factory in the rear.
4) Have you confirmed that your wheel alignment is within spec?
Yes, many alignments over the course of ownership. I generally get an alignment done with every set of tires. I've HAVE had one or two that were significantly out of spec on at least a wheel or two (no doubt due to the rough roads I typically drive on).
5) Do you carry a lot weight in the trunk?
Nope.
6) How many miles are you getting per set of tires and which brand/model tire have you tried?
I've had two sets of the OEM Goodyear Eagles (each lasted approx. 20k miles) and three sets of Michelin MXM4s (each good for approx. 35k miles). the fifth set (MXM4) is still on the car and relatively new. I rotate the MXM4s myself in the driveway every 5k miles or so. I should mention they're 19" wheels in case that wasn't obvious.
7) What's your proportion of unobstructed highway miles compared to congested or metro driving?
As mentioned above, about 50% rural 2-lane roads (some in pretty terrible shape) and 50% un-congested freeway driving at ~75-80mph.
Perhaps I have the anomaly but I'm surprised to see your rear tires wearing twice as fast as the fronts, and the fact that you're on your 5th set of tires. I have over 104K miles and I'm almost done with my 2nd set of tires.
Interesting for sure. I have no doubt that my commute and local roads are a major contributing factor, with very old, rough pavement that literally grinds the tires down prematurely. But I definitely see much faster wear on the rears, and have always attributed it to them doing 100% of the acceleration and 90% of the braking via regen.