The safer alternative is clearly to begin the takeoff from the end of the runway, yet our happless BA pilots chose otherwise.
Not really, in this day and age, and on modern jets. A take off from the full length would have used a higher derate, and consequently the aircraft would need more runway, than from an intersection where a higher power setting would be used, and consequently less runway needed. A point often overlooked by the "runway behind you" brigade.
Regardless of your views on whether the captain should taxy the aircraft or not, I am at a loss to see what difference it would have made in this incident. I mean, he was on the flight deck, right? So he didn't do the take off brief, but presumably he listened to it?
Apart from 411a, who clearly came forth from his mother's womb, wearing 4 stripes, and a set of pilot's wings, we all have to start somewhere. IMHO, but only having known BA SOPs, the more you can get the FO to act as captain the better. We are all qualified P1 on the aircraft, and it will make the transition to captaincy that bit more straightforward when the time comes. In addition, many folk are vastly experienced in the RHS, either from a military background, or having held commands in other airlines.