Hyphens not needed
no hyphens - 57 years old is what you are.
Yes it should.
If you're using the phrase as an adjective (example "I hate the end-of-the-year audit!") then it will definitely need the hyphens. Otherwise, the hyphens are incorrect.
Most people would spell it sixteen-year-old child. But over the last 20 years, people are ignoring the hyphens.
Yes it should be hyphenated.
There are no hyphens in the word ago.
It should be "up-to-date". You will see it in many instances written "up to date" without the hyphens, where each word becomes a separate and different part of speech, which may be confusing. (Hyphens are grossly and woefully under-used in adjectives.)
You use hyphens to make compound words that are not recognizable in common usage.
It changes the hyphens into end dashes.
If you're using the phrase as an adjective (example "This easy-to-use remote is great!") then it will definitely need the hyphens. Otherwise, the hyphens are incorrect.
It changes the hyphens into end dashes.