BRIT 312 sir; I think that you will find that the 'estmated' 1 Tonne overweight does not take into account 19 suitcases not on the loadsheet, placed in the aft hold. We can only 'guestimate', but these were good folk going on a world cruise, these cases are unlikely to be very light.
Also remember that it has not been satisfactorilly explaind why there was large amounts of right rudder applied early on the T/O roll, with no heading change. What you have to realise about the 'bumpy' runway is that the rougness was at the extreme end; ie the beginning of the T/O roll, and that was where the damage was done. Remember, the early part of the T/O requires NWS as well as rudder for full control. By the time the A/C was travelling fast enough for the rudder to become effective, the A/C was already well over to the right, because of the U/C problems.
Your point about flying at the backside of the drag curve is of course correct, however there is no evidence that there was a detected loss of B, G or Y fluid. As I said before,did not have sufficient IAS, and the A/C needed to climb and accelerate, but because of reported factors it could do neither, once engine 2 was shut down there was absolutely no chance of survival.