Sounds like very substantial progress Martin - a really useful report.

Did you run any additional seal around the inner face of the bottom of the doors ? (where they seal against the car body below the door aperture). In addition to the other areas you have noted, on mine, there are gaps along this section and these seem a possible cause of some water ingress onto the stainless steel scuff plate that runs around the door aperture when it rains or I use the screenwash (another possibility is that water is getting driven in past the hinges at the door front edges - again by the slipstream). I'm having the draughts / leaks and possible misalignment of the door (hinging angles) with respect to the car body - both sides - looked at under warranty in March.