With the colossal caveat that I am only a **consumer of** Unicode's deliverables, I could speak briefly to the concern at point #3:
On Mon, Oct 31, 2022 at 11:20 AM Till Jaeger via lists.spdx.org <jaeger=jbb.de@...> wrote:
This is certainly inconvenient, but the Unicode site does host quite a few items with practical application, but which aren't under the "DATA FILES" and "SOFTWARE" hierarchies spelled out in "B" of the TOU.
Namely, there is the whole "Unicode® Technical Site" at the entry point https://unicode.org/main.html ... which is different from the "Unicode site" at the entry point https://home.unicode.org/
Some of that "Technical Site" material covers projects and committees; there are also older documents, proposals, some data tables, things called "annexes" that I'm never 100% sure I understand the status of, and so on. My guess would be that there is a lot of legacy material from the organization's history that simply doesn't have a clear-cut, select-a-license-from-the-dropdown option.
Fortunately, a lot of that material is mostly needed as references, but I can certainly see how occasions would arise where quoting from it is necessary to squash a bug. I've had people attach screenshots from really old Unicode docs in discussion threads. So I wouldn't attempt to weigh in on the other issues (certainly keeping the text up-to-date sounds vital), but merely dropping the license from SPDX would likely affect (a few) projects downstream.