Thank you for that hugely informative essay.
I do think that, according to my understanding of it, you sort of missed the point regarding identity politics. It is primarily about people self-identifying as a member of this or that group, as opposed to people assigning people to groups based on physical appearance — or any other criteria — much less being about assigning attributes to individuals based on membership in a group. From there, it is concerned with people in those groups identifying political interests the members of the group have in common.
Also, I thought you might perhaps find interesting something I have published in Medium, “Re-thinking Individualism.” I argue for a new and different understanding of individualism and especially its implications for governing governance. In particular, I seek to convince people that Locke’s philosophy conveys a different individualism than he (or anyone since him has) realized.