[MarinerZ4C]

Have you solved this issue? I didn't see a mention of the ignition switch - has this been changed out? If not, you may want to try changing switch module (not the key cylinder, but the switch).

On our E85/E86 platform cars, the ignition switch passes power to several circuits directly, without an extra relay, and the switch can look good, but have enough wear to pass inadequate current. This can lead to a 'no-crank, no-start'. Last Summer I had a 'no-crank, no-start', and I replaced my ignition switch - this was at ca. 92K miles. I could tell it was not the first replacement, because factory paint dots on the screws had been disturbed. I have not had a problem starting since replacing the switch.

I see you have been down several roads on this, so it may not be the problem, but time and difficulty to replace are not bad, and the part is between $40 and $100 (the BMW one is $$$, of course).