snappa, the central diff lock just locks the transfer case so you get the power split between the front and rear diffs. If you are drving in soft sand for instace, and you start to get hung up you will find that only one wheel at the front and one wheel at the back will spin. This will happen less in LSD's, but will still happen. What a diff lock does is lock the diff so both the left and right wheel are always travelling at the same speed, so you won't have one spinning and the other stationary. If you go one further and install front and rear diff locks like I have you get all four wheels turning at the same rate at all times, gives you tractor like traction.
And Poodroo, it's not cheating!! Although it does make the easier stuff even easier. The problem is it gives you the confidence to go places better left untravelled!!
As for the paj, it would be able to do the job. My Father-in-law tows a 2 tonne trailer behind his V6 NM Paj with stock suspension on North Straddy. No problems. The only thing I would reccomend with a mono-coque chassis is getting an equaliser strap for snatching. You thread it through the eye of your end of the snatch strap and then attach it to both sides of the chassis, thus sharing the load down both sides of the vehicle minimising any twisting that the weaker type of chassis can't cope with.
Brett