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Interesting thread, I also read through the TDI EOC thread.
To the OP, I think your a little crazy to go EOC'ing a brand new car under waranty...If you are trying to drive a car to get great mpg, it's probably because you want to save money. If you want to save money, then why are you buying a new car that gets much worse mpg than a 1988 Honda?
I work with Turbos and do some failure analysis. However the only turbo vehicle I own is a 7.3 Turbo Diesel Excursion. I've had the chance to dyno a 7.3 while checking turbine housing and bearing housing tempature vs. EGT. At 1100 degree EGT, post turbo, the Turbine housing was around 650-700 degrees and the bearing housing was around 500-550 degrees. This was under a high load on the dyno, thus the high EGT. High EGT is associated with High Load. I wouldn't get caught up on how much boost you are making.
I don't really like the idea of using an electric pump, to many failure modes associated with that, and you'd have to create some significant pressure to get any real benefit, and that would take quite a bit of electricity to make that psi.
Turbo seals are more like piston rings than O-rings. They are designed to always leak a tiny bit to keep them lubed. They are very durable and are difficult to damage, the bearings should die from coking long before the seals, key word is should.
I could definatly see P&G being a potential problem, but as said, it's all about the tempature of the bearing housing and oil, additionaly if you are at high boost (high turbine rpm) and just cut the engine, you would loose oil pressure on a shaft turning 150,000rpm or more! That's not a good idea at all.
I see plenty of hot shut down issues. It starts as a varnishing of the shaft and bearings, then gets worse as the varnish builds and can eventually lead to wear and excessive shaft motion and then.....That being said, you typically have to abuse the turbo very badly to get varnishing, ie. hot shut down and worn out oil. Keeping a good and fresh synthetic oil in the engine goes a loooong ways towards preventing these issues. Blah Blah Blah....you get the idea.
I'm a bit crazy, so I would probably EOC, then tear down the turbo regularly to see what's going on. If you can manage the load, temp's and turbo rpms, you could probably do it without causing varnish.
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