Hi,
As said above I wouldn't start removing the vertical cabinets which provide bracing for the structure. I have a '91 Sky Cruiser I and it has the big moon roof running about 5 foot along the centre of the camper - that makes a big area that is not structurally supported, so it needs as much rigidity as it can get. The sky cruiser II might be a different design, plus yours is later too.
I have 4 jacks on mine - wouldn't fancy 3. Shouldn't be too much work to change to 4.
I keep chasing rot through my Sky Cruiser and replaced the roof a few years ago - the main structure of the roof was sound, just the top surface of ply was rotten. I put much thicker marine ply on and welded a checker plate aluminum roof on with roof rails and solar.
My weight plate said something like 1400#. I know it weighs a lot more than that, but I probably haven't helped with some of the rebuild work. I weighed my truck and camper last year and subtracting the weight of the truck: the two of us, our gear, the junk we carry in the truck, the camper and its contents, came to nearly DOUBLE that weight :E
Any weight you remove from the back of the camper is good since that hangs out behind the rear axle of the truck, so removing weight there will improve your centre of gravity.
I don't think there is much info out there about Shadow Cruiser. I think they went bust, then got taken over, made some more campers early 2000s, then some trailers. Not sure if the name is still being used on trailers, but it isn't on TCs.
If you can get some pictures I can see how similar your camper is to mine.
Steve.
'07 Ford Ranger XLT Supercab diesel + '91 Shadow Cruiser - Sky Cruiser 1
'98 Jeep TJ 4.0
'15 Ford Fiesta ST
'09 Fiat Panda 1.2