[svxcuseme]

I've read this entire thread from start to finish. I've had similar issues with 3 of my SVX's. On two, it was timing. One had timing off by a few teeth ...EEK! The other had timing off by one tooth... and it caused the car to run like crap (one cyclinder not firing).

Two questions / two cents.
When you checked the timing, how did you check it? Did you verify both cam marks aligned exactly with the mark on the back of the cover and the crank was pointing exactly at 12? Not trying to say your check was not adequate, just want to make sure. My experience is that most shops cannot time a subaru to save their life!!!

Another issue could be two or more bad coils. I did not figure this out until I started swapping two coils out at a time...I went months trying to diagnose a skip/shutter and it was two bad coils. But then my problem was more variable misses, not a constant misfire that bad timing can cause.

Neither could be your issue but you've just gone through so much! I'd like to see you figure this out rather then leave it to the Subaru dealer and a 50/50 shot that you will get a good tech!