Here is a place where I think the water is coming from
I tend to agree. You need a new person to do this right. The original builder did it wrong.
The place where the water damage shows up the worst is the place where the water exits. That appears to be the bottom of that trim board. You've seemed to identify the place where the water is entering, too. That's the hard part. But it looks like you've traced it. Now the really hard part is to install the flashing correctly without removing too much siding and shingles. That's why you need a new person to do it right. I'd bet on a zreo percent chance the original builder will do it right.
Thanks for the reply, Aidan. So, you saw the other pics in my series. I couldn't figure out how to put them in one post. So, what started out as a trim board piece is indeed a bigger issue? He said he would look at the issue, but who knows if he will take it as seriously as I am right now. The water has completely drenched the trim piece. Looking above it made it easier to see why. This is going to cost me a fortune to fix. He is still building in my neighborhood and I have the power of the net. He better do what is right.
Yep, definitely needs some flashing fitted up under the siding above the eave. Maybe a little caulk below the eave where the siding meets the trim?