I don't think it's necessary.

Here's the relevant section of the hyphen entry:

Many combinations that are hyphenated before a noun are not hyphenated when they occur after a noun: She works full time. She is well aware of the consequences. The children are soft spoken. The play is second rate. The calendar is up to date. (Guidance changed in 2019 to remove the rule that said to hyphenate following a form of the verb to be.)

But use a hyphen if confusion could otherwise result, especially with longer compound modifiers or those that are not as commonly used: The steel surface should be blast-cleaned. The technology is state-of-the-art. The test was multiple choice and fill-in-the-blank. He will work arm-in-arm with the director.

Do you mean hyphenate? Yes, I'd hyphenate that use.

We use the term fintech (lowercase) but not the other term.

Here's the entry for the general terms. If a particular university has a specific name for a degree that falls outside the general guidelines, use that specific style.

If mention of degrees is necessary to establish someone's credentials, the preferred form is to avoid an abbreviation and use instead a phrase such as: John Jones, who has a doctorate in psychology.Use an apostrophe in bachelor's degree, a master's, etc., but there is no possessive in Bachelor of Arts or Master of Science.Also: an associate degree (no possessive).Use such abbreviations as B.A., M.A., LL.D. and Ph.D. only when the need to identify many individuals by degree on first reference would make the preferred form cumbersome. Use these abbreviations only after a full name — never after just a last name.When used after a name, an academic abbreviation is set off by commas: John Snow, Ph.D., spoke.Do not precede a name with a courtesy title for an academic degree and follow it with the abbreviation for the degree in the same reference.

Yes, all of that is correct.

We lowercase such uses.

We're sticking with the apostrophe.

awhile.

We're debating these very questions. Stay tuned ...

Thanks for your good wishes! The healing is going very slowly, as is the typing. Apparently this could last for many more weeks.

As for your question, it's one of those judgment calls and not everyone makes the same judgment. It comes down to whether you think the meaning is clear without the hyphen. The rubasse entry is actually from Webster's New World College Dictionary, which you get as part of your Stylebook Online subscription. Webster's uses the hyphen in ruby-red as a modifier. I would argue that it's perfectly clear with no hyphen and thus the hyphen isn't necessary.

Maddening, I know.

This is a judgment call, but I'd say no hyphen is necessary. The term black sand beach is commonly recognizable to mosr people who would be reading about beaches. The hyphen doesn't add clarity and thus isn't needed.

Yes. Spell it out and don't use the acronym when writing for general audiences. On second reference: continuing education or continuing ed.

Yes, capitalize it as part of the "word."

You're right in wanting to avoid confusion that could occur with lager to bourbon if there's no hyphen. Bourbon-barrel-aged is a bit clunky, but it's better than being confusing. 

Our colleagues at Webster's New World College Dictionary, which is where you're seeing that entry as part of your Stylebook Online subscription, thank you for pointing this out and say they will consider a revision. Informally, you're right that it's often used as a noun.

Yes, that's fine.

Capitalize it. Here's the entry:

Capitalize when used as the proper name of the planet, lowercase for other uses. The astronauts returned to Earth. He hopes to move heaven and earth. She is down-to-earth. The moon, Earth and sun lined up to create the only total lunar eclipse this year.

See planets.

You could use AP style, which is gray:

gray  Not grey. But: greyhound. 

No. The period always goes inside the quotation marks in AP style.

No, it's correct. See the first sentence of the section in question:

If a paragraph does not start with quotation marks but ends with a quotation that is continued in the next paragraph, do not use close-quote marks at the end of the introductory paragraph if the quoted material constitutes a full sentence. Use close-quote marks, however, if the quoted material does not constitute a full sentence. For example:

But: He said he was "shocked and horrified by the slaying."

I don't think quotation marks are necessary. The meaning is clear without them. On another point, AP style doesn't use the Oxford comma in simple series such as these:

Some of the negative age-related words that Levy used in her study include decline, dependent, dementia and dying, while the positive ones included guidance, wise, insightful and enlightened. 

We'd avoid such constructions. How about just: Joe Smith, the show's director, writer and producer, created ...

We refer to, for instance, the indigenous Maori people.

It's probably clear in the context without a hyphen. It could, indeed, go either way. There's no absolute on this one!

Yes.