I dont think your motor needs to be rebuilt/replaced.
Now, I do think your car is cursed. lol
I think this is what Blue is suggesting to use to check the misfire. Unfortunately, #4 is the biggest pain to get into.
https://www.amazon.com/Tool-Aid-36350-Line-Checker/dp/B000VULAQC
I have something similar but without the injector testers.
I'm in the same boat as you. 4 places and 4 different answers/suggestions/costs including the dealer. If mine continues I am having it shipped to KC rennsport for him to take care of but so far I am doing better (at the moment anyway)