AK,
I have done everything you have specified. I have inserted and re-inserted that dipstick many times in 3 conditions: hot, cold, warm. They all point to oil consumption.
I also do not have any oil leaks. As a qualifier, though a computer-geek by profession, my primary hobbies are rebuilding german cars, engine maintenance, suspension work, crotch-rockets, and anything that deals with 'speed.'
I have also searched the web today and found a few postings where the Nissan VQ-engines were reported with not-so-normal oil consumption. I guess they also have an 'oil consumption' test they could do.