It's been some time since this thread was near the top of the pile.
However, due to a "no-fly" day I decided to re-read it. I might be mistaken but it appears that more than one thread was merged into the original.
CAA Safety Notice 006/2014 was mentioned. This has been replaced by Safety Notice SN-2016/001 and is downloadable from the web.
I think it's worth pointing this out because many of the more contentious points discussed in the thread have been addressed by the CAA in that document. Almost as if the CAA have been following this thread..... It's well worth a read!