Checking the alignment as in the photo only shows where the blade ends up after the cut has been made. Unfortunately, it would seem that the blade isn't tracking at a perfect 90 degrees, only ending up there..
It almost seems as if something is twisted or as you mentioned " that the hinge pivot casting is not parallel to the blade spindle casting." to account for the cuts you're getting.
Sometimes you just get a lemon, if it can't be adjusted to the point where it cuts reliably, I would have to let it go and stop chasing a problem that can't be fixed.