Jevy,
Just came across your thread and am sorry about your back issues that have had such impact on your life.
I have a few comments and suggestions if you still have the trailer.
1. Do the laws in your state/country allow the number of projections outside the trailer body and the amount of tyre beyond the guards on both vehicle and trailer? Here in Australia the police and registration people would have it off the road as soon as seen.
2. you could make a simple frame on the trailer that would slide out to provide for slinging the hammock if no suitable trees were available.
3. Why do you need a generator? With a battery charged from the vehicle and only a few lights and the fridge I would think you could do without it. A single solar panel would help in summer. More peace.
4. It is possible to adjust the pressure in gas struts. The guys who recharge old ones can do it in situ and get the balance right.
Hope you are ok and still able to enjoy camping.
cheers