I think I challenged twice as to what I should have done,and since Google will be sending people here, advice to others as well.
Not what should I NOT have done, which is what this thread mostly consisted of, but what should I have done. There are no wrong answers here if it is your honest opinion. Keep my mouth shut and junk it or trade it off; run it though the shop over and over again; or something totally different; exactly what?
And, to other folks who are coming here, via a search engine, unless the moderator deletes the thread, what advice do you have for them when they get an intermittent that they cannot diagnose? If it is your honest opinion, as opposed to more personal attacks on me, I am not going to criticize.
This board has helped hundreds, perhaps thousands of people fix strange problems on their cars, over the years. Give them guidance on intermittents. There are many thousands of intermittents every year in the US.