Yes it should.
Hyphens not needed
no hyphens - 57 years old is what you are.
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.
Yes, "year to date" should be hyphenated when used as a compound adjective before a noun, as in "year-to-date performance." However, when it appears after the noun, such as "the performance year to date," no hyphens are needed. Always consider the context to determine the correct usage.
Yes, you should use hyphens in "eleven-year-old" when it functions as a compound adjective before a noun. For example, you would say "an eleven-year-old child." However, when using it as a predicate adjective after a verb, you do not need hyphens: "The child is eleven years old."
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.
Yes, there should be hyphens in "thirty-year-old" when used as a compound adjective before a noun. The correct phrasing would be "a thirty-year-old civil war." The hyphens help clarify that "thirty-year-old" is a single descriptor for the civil war.
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.
Yes, "year after year" should be hyphenated when used as a compound adjective before a noun (e.g., year-after-year performance). However, it is not hyphenated when used as an adverbial phrase (e.g., they met year after year).
No, you should not.
Yes, when used as an adjective. Year-to-year is hyphenated when used as an adjective: year-to-year comparison, year-to-year budget. Year to year is not hyphenated when it is used as a time period: We come back to this same beach year to year.