Sorry to read about this, and I agree this must be really annoying. Unfortunately I found my MK8 a huge boost in quality from the MK7, but with way too many rattles and noises. Coming from the doors, from the panoramic roof, from the engine... It just made me crazy in the beginning. I fixed most, some with some help of the dealer.
Regarding the heat pipes; I had this issue as well and it is known by Ford. I found a topic which I can't find now that Ford has proposed a solution for it, but it's easy to apply it yourself. You have to tie-wrap the two heating pipes near the plastic mount which connects them. This prevents them from moving too far apart but doesn't push them together, that's where the tie-wrap comes in. Don't over tighten it, it should only put some pressure on the pipes to keep them together and change the resonance frequency of the two. Hope it helps..
But again, the MK8 is just full of sounds and rattles if you ask me. I really like the look and feel of the interior compared to the MK7, but still there is too much plastic giving rattles and ticks all throughout the car. Fix them one by one, and after about one year I found it acceptable. ;-)