I just wanted to let folks know that the starting problem was the crank sensor. After reading posts on various BMW sites, that seemed to be the most likely culprit, after I'd eliminated the fuel pressure and spark issues.
I was in a rush to get the car fixed (my wife's), so I picked up the part at Auto Zone for $79. My brother and I installed it in about 4 hours (it would take about 2 hours after doing it once).
The problems in installing it are just getting to it, and then getting the screw out that was holding the sensor in (locktite). However, another problem was that in repeated attempts to start the car, it was flooded so badly that there was gas in the air intake ducting. We had to take the spark plugs out to let the cylinders dry out, and wiped the gas out of the air intake ducting, then let it sit overnight. It started up the next morning and it is running perfectly now.
If anyone needs advice on how to get at the crank sensor, email me directly as I don't normally monitor the threads on this site.