Interesting reading, and I feel for you having to experience all of those issues especially as you are so reliant on the bike for your job. 2K miles in 3-4 mths, that's going some !
I have had a few cutout's on my old crossfire-e (purchased in Aug '06), however, not seen it happen in the same way (as your video). Mine would cut out, and then by just powering the battery and then turning on the display, would then cycle a few more yards, and then it would go off again. Sometimes, ONLY reinserting the battery would cure it, and on my way again, perhaps the problem not returning for a month or so, or 2-3 times in the same week, no pattern.
I have just replaced my crossfire-e with a brand new one, 3 weeks old (got a great deal, sold my old one). So far no cutouts at all in 200 miles, but early days. Perhaps mine is so new they have fixed the problem with the motor ? Hope so, but it does sound a bit random as to which motors are affected considering they have already swapped out you motor previously ?
Good luck, please keep us updated on how it goes, as I'll be running mine for the next couple or so years again, so will be interesting on how it pans out and how Halfords address the issue with existing bikes that have the problem (or though not as severe as yours).
Be interested too on how you get on doing the miles you do. I did 4k miles on my old one, no issues with wear and tear other than the usual consumables such as brake pads, cables etc