How about Mule Tape
or Bull Line
That is a good idea.
I had no idea that stuff existed.

I cant fing any specs for weight/unit length though- have you any idea Nacra?

I think dyneema is a little overkill for webbing in this case. Price and strength.
As Ikemouser said, the weight of the tree straps are significantly heavier than the weight all the tarp, hammock and guy lines put together.

I think it is possible to cut a chunk of weight and bulk, remove the weight penalty for protecting trees, and avoid messing about with putting sticks between the suspension and bark-this can only encourage the LNT philosophy further.