Man you're having a hard time.
My thoughts are the same, plug in with
Vagcom, check to see if the TCU is seeing that you've selected the gears when you move the lever. If not the gear selector switch is dead. It's on the outside of the gearbox and can be replaced in situ. It's fiddly but possible.
I think that the reason that you can't pull it backwards is the almost 'hill control' type feature that these (well the last 3 I've driven anyway) gearboxes have that they won't allow the car to roll backwards when in a forwards gear.
The easiest way I can think of moving it is to remove all of the bolts from one of the front driveshaft's inner CV joint to the gearbox and allow it to turn freely against the gearbox flange. The tight fit of the driveshaft should hold it in place and not allow the driveshaft to drop down. This is for moving it very small distances only, i.e. to manoeuvre it onto a recovery truck or around a garage only! Once one side is free, the front diff will allow the other wheel to turn freely and the centre diff will allow the rear wheels to turn. Jacking up one of the front wheels (and using the jack as the 4th wheel) should have the same effect.
MG
