No hyphen in any use. 

AP style doesn't use the accent marks. You're certainly free to use it if you prefer.

Yes, that looks good. 

Yes, it definitely applies to those as well.

An eight-week course, but an 8-week-old child (numerals with ages). Yes, it's confusing. Yes, we're hoping to add clarity. It will take some time.

That's correct if you have only one daughter. Use the commas.

If you have two daughters and are talking about just one of them at a time, then it's

Our daughter Charlotte continues her work and our daughter Emily moved to Switzerland.

In AP style, we never put an entity's abbreviation or acronym in parentheses following the full name. Our guidance is that if you want to use the shorthand later in the story, it should be familiar enough to readers that they can understand it. Otherwise, don't use the shorthand and instead just use a term such as the university, the group or the agency on later references. Here's the relevant section of the abbreviations and acronyms entry:

AVOID AWKWARD CONSTRUCTIONS: Do not follow an organization's full name with an abbreviation or acronym in parentheses or set off by dashes. If an abbreviation or acronym would not be clear on second reference without this arrangement, do not use it.

Names not commonly before the public should not be reduced to acronyms solely to save a few words.

We're working on developing some consistent guidelines. It's a work in progress. I'd say Class C felony for now. (But does it do the readers a service to use that level of detail/terminology? How about just calling it a felony and then spelling out what it entails.)

Use the plural, hookahs.

Lowercase it.

It's hard to read that way. I didn't understand the meaning the first time or maybe the first two times I read it. I'd either add a hyphen or rephrase:

They make millions income-tax-free.
They make millions free of income taxes.

(And tips on how to do that would be appreciated!)

I assume that only two students are being written about? If that's the case, how about this:

The judge ordered the sixth-grader to stay 50 feet away from the other student for one year after he found that the defendant stalked and bullied the student (or the boy or the girl,  or the youth) again following the Nov. 13 case.

A couple of related entries to note:

Generally acceptable to describe males or females younger than 18. While it is always inaccurate to call people under 18 men or women and people 18 and older boys or girls, be aware of nuances and unintentional implications. Referring to black males of any age and in any context as boys, for instance, can be perceived as demeaning and call to mind historical language used by some to address black men. Be specific about ages if possible, or refer to black youths, child, teen or similar.

A minor event. Anything that causes death, injury, notable damage and the like is not an incident.

It's the singular: ... is their brand. That's correct regardless of the order of the material within the dashes. But you might try switching the order to see if that sounds better to your ear:  The brands that understand this realize that their online presence — their social channels, digital content and website — is their brand.

It's then-President Barack Obama.

I suggest going back to her to clarify whether she means Miami, Miami Beach or Miami beaches (or all three). Miami Beach is a city that's distinct from Miami. So don't change it to Miami unless you are sure she meant the city of Miami and not the city of Miami Beach. Or beaches in general.

Looks to me like Webster's New World College Dictionary doesn't use italics, and I don't know why they would. The word is commonly used in English without italics.

I think it's clear, and certainly more readable, without the hyphen.

It's just the last name on second and all subsequent references.

Here's the relevant section of the essential phrases, nonessential phrases entry. I've added bold for emphasis:

DESCRIPTIVE WORDS: Do not confuse punctuation rules for nonessential clauses with the correct punctuation when a nonessential word is used as a descriptive adjective. The distinguishing clue often is the lack of an article or pronoun:

Right: Julie and husband Jeff went shopping. Julie and her husband, Jeff, went shopping.

Right: Company Chairman Henry Ford II made the announcement. The company chairman, Henry Ford II, made the announcement.

I'd make it "what-if" scenarios, with the hyphen and quote marks. But we don't have a specific style for it.

This is one of those gray areas. Many combinations after a verb are clear without hyphens. Others benefit from that added bit of punctuation. I'd argue for dishwasher-safe for easy care.

We would use hard rock mining. If you're writing for an industry-specific audience, you of course might prefer to use hardrock if that's more prevalent in the industry.

I'd hyphenate as an adjective. I'm not sure how you'd use the term as a noun. But if there's a reasonable way to use it as a noun, I'd hyphenate that, too. And lowercase it.

Electrical, for something related to electricity.