Check out the "Dark Side" section here on this Forum. It is all the way down on the bottom of the main Forum page.
That may answer some of your questions. BUT I don't think there is a definite answer to most your questions, so a sticky will not help someone on the fence get the info they need to make a decision.
Yes I run a car tire and have for over 50,000 miles on two different bikes.
NO I did not do it for high mileage ( I typically get 18,000 out of mine) or a cheaper tire. If you really want the info just ask me or anyone that does run a CT...