Can any EK drivers let us know if this service was planned direct to Dubai & how the take-off performance should have been using Rwy 16 with 5 kts downwind at such a heavy weight?
Yes, it's a direct service.
Performance should have been fine, although I don't have figures to hand. 5 Kt tailwind would have given a lower "flex" thrust (more thrust) and a lower V1 but that's it. Certainly not limiting.
You got using the cross incorrectly
EK still using the Maltese Cross for rotation?
I believe the software has been modified so that the cross disappears when the nosewheel strut extends. If so, you CAN NOT fly the rotation with it 'cos it's not there.