Let me say that I think with only two small exceptions, you have done a fine job with contemplating life before death.
First let me say that I have a small advantage over Stephen Hawking and you in that I have the brain power plus more experience and more years to put it all together.
But you are spot-on with: “In the forest, not even death goes to waste. Fallen trunks lay scattered like pick-up sticks, food for mushrooms, moss, and saplings. Dead trees still standing are now condominium developments for birds, squirrels, and bugs. At my feet, the detritus of leaves and needles provides nourishment for the next generation.” I do think you miss part of the point though. That is the point of life is to continue the existence of all living things.
As pointed out in the old TV series, “Six Feet Under” - death is the opportunity to remix our bodies with the ecology of life. Burial in a shroud is depicted in the series when one of the central characters is buried in that manner. But also depicted is the difficulty presented by state laws mandating “formal burial”- meaning in a costly nature-resistant coffin and the costly service of a “certified funeral director.”
While still alive (apparently tests show that I could live until the year 2030 - 7 years from now) - I can participate as you do, focused on what I call working for our species. You see, our species is truly new and unique. While inclined to violence and killing, we are still the only species to have developed extensive relationships with other species and are now researching the subject of sentience as never before. We are the only species capable of doing that!
With all this in mind, I can honestly assert that there is no such thing as futility.
I look forward to seeing more of your work. I felt almost alone in my beliefs but works like yours assure me that I am not really alone.