Lots of food for thought there, thanks for the detailed reply.
Regarding the subframe bolts, it was a calculated move in the respect that they hold the rubber mounts to the car with the subframe held to the mounts via standard bolts, theory being there will be some give in the mounts to reduce stresses on the bolts despite the manufacturer telling me they are almost identical to 8.8s in every respect.
Unfortunately in this area I feel I have no choice since the fronts literally sit in water and if you look back through my thread the old ones has literally disintergrated which would be far worse than plain stainless.
If only we had the strength of 8.8s and the corrosion protection of stainless.