It's not clear to me what you mean by value. To say that something has value is to say that is more valuable than other things. This is why at the end of your progression valuing everything becomes equivalent to valuing nothing.

This is true for all definitions. If there is nothing that is not valuable, then the term "value" becomes semantically empty.

This has nothing inherently to do with altruism. Every agent makes value judgments, and value rather than being treated as a binary, is typically treated as a real number. The agent is thus free to choose between any number of futures and the infinitude of real numbers assures that those futures remain distinct, so Armstrong 7 should never be in turmoil. Additionally, this is more or less how human operate now. A pretty rock or an animal may be valuable, but no one is confused as to whether or not that means they are equivalent in worth to a human.

Interestingly, you use, and then deconstruct the binaries of sentient/nonsentient, living/nonliving, etc, but you don't apply that same tool to the dichotomy of altruistic toward/not altruistic toward.