The 767-200 does not have a fuel jettison system, the -300 does and I assume the -400 does as well.
No such message as "LE STAB ASSYM" as far as I'm aware, possibly "LE SLAT ASSYM".
Looking at the photo, the main gear doors appear to be open, implying manual gear extension. This, coupled with a possible flap 20 landing, would imply a loss of the centre hydraulic system.