"In particular is the 128 dimensional T^2 hyperspinor space the same as the E8/SO(16) = 128?"
I don't have any reason to believe it is or isn't. Tony Smith thinks so, but I am unwilling to lead the maths. I prefer to be led, even if led astray. At least it won't be my fault.
"Jordan J^3(O). This is I think more general than the Leech lattice, or embeds the Leech lattice."
Wilson, at U of London, and I have independently represented the Leech lattice over O3. Anyone with any interest in J^3(O) will naturally point out that there is a nice copy of O3 in J^3(O). I don't know if this is meaningful. If one could show that there was a bilinear of trilinear multiplication on the Leech lattice as a subset of J^3(O) that closed on this subset, then I personally would be hugely interested. But yes, one can stick it into J^3(O), but without some further interesting structure ...
"I was wondering if you have done any work on this and automorphism of the FS "monster group.""
No. I of course find the monster group enticing, because it is exceptional, but I haven't got around to looking into it.
As to your paragraph 2, this leads into the quantum quagmire. If you can find two people who agree on much of anything in that quagmire, let me know. Meanwhile, the level of disagreement means to me that we are not ready to understand at a deep level.
"... it appears to be a collapse of objectivity to just assume mathematics is a sort of game or human invention. I am at a stage where I have not the faintest idea what the deep relationship between mathematics and physics is."
This is a hard one, because one has to define what one means by mathematics. I think of it as a thing that is there even in the absence of any intelligent life or any conception of consciousness. Many will likely give this idea a label named after a dead Greek and think they understand. Maybe they do. Anyway, in the presence of human intelligence we have this notion of Ur-mathematics, and we have the human symbols and formalism that is our lens onto this world. So, ignoring the invented formalism, I think of physics - I'm just making this up, but it sounds good to me - anyway, physics crystallizes on the exceptional, generative, and resonant bits of this Ur-maths, for only there is there a structure rich enough to nurture it. And to give rise to us, for what that's worth.