Though persistant you may be, scientific you are not. What you must address is: what is changing when you do all these activities. Your various actions kill the car. You act as if that is a unique act. You are either stopping the fuel pump or the ignition. The car will live through an EHA failure unless it is getting a mighty powerful wrong signal; which is easy to monitor.
Determining which is the next step. The answer will not jump on you, as you fram around.
I don't know where in Georgia you are, but if the car is driveable I will donate a Saturday to showing you how we would test these items and we WILL figure your car out. We might even throw a part or two at it (all diagnostic tools to evaluate a hyphothesis - we won't replace anything until there is a scientific question to be answered). When we get an answer, you can fix it.
We could even sell tickets, maybe! Anyone else want to fix this beast?
Bosch Master, ASE Master, L1
33 years MB technician