James,
After reading this plus the flash to pass thread on the other forum, I suspect that all the points you're mentioning are related to one single piece in the car that manages all those functions, that is the Multi-Function stalk on the steering column.
Have you removed it yet? If so, please let me know what the procedure to remove it is (could not find this on the Haynes manual) as I believe mine is going down the same path as yours.
Also, do your turn indicators ALWAYS self cancel? Do they ALWAYS engage when you use them... or do you sometimes have to hold the stalk down for the turn signal to work?
Thanks,
Andres