Didnt read the entire thread but here are my thoughts. BMW has made both great and not-so-great cars. I had an e30 3 series (made from '84-99 I think), and it was a really fantastic car (ie reliable, well made) that I put over 300k on before I sold it. And currently my wife has an '05 X3, which has also been a great. reliable vehicle.
What I would do in your situation OP, is join a BMW forum and ask specifically about the model and year of the car you're thinking of buying. You'll get a good idea of the strengths and weaknesses of the car. I did that with my wife's X3, and my '90 Miata before buying. Good luck!