-The area you describe is not far away from the NACA vent outlet.
-It is not uncomon on Manch 145s to have max fuel
-Like most other swept wing/dihedral a/c fuel enters the vent pipe when full.
-At rotation fuel in the vent line travels aft and outboard into the surge/vent tank.
-As it started the turn fuel would not have had time to be sucked back into the main tank and it then vents overboard.
In answer to your other question there is potentially a 2,300Kg difference between MTOW and MLW this would take more than 2 hours to burn off as we dont have the ability to dump.Clearly in a serious emergency we have the option to land overweight.
