Marlin, I have to admit that I have never weighed mine, so am just going by the published curb weight for the JDM VX, and that is 1794 kg, or 3950 lbs.
Most other true full chassis 4 wds in Australia are well over 2500 kg, so the weight difference is significant.
I also agree that all government DOT requirements could have had a lot to do with Isuzu not recommending towing with the VX. It wasn't only in America.
Sue, you won't have any trouble towing your toy box provided the draw bar is full length to keep it stable, and that is the trailer builders work, not yours.
I tow my boat on a dual axle trailer - 1350 kg all up - with no problems, but I have been towing boats and caravans all my life, and drive accordingly.
I agree the VX can be used for towing - just have to keep it realistic.
PK