It depends on how it is used. When it comes before a noun and acts as an adjective modifying that noun, it is hyphenated: We expect the holiday party to be a well-attended event.
However, when it is used with a linking verb and does not come before a noun (that is, when it is used as a predicate adjective), it is not hyphenated: The free outdoor concerts were typically well attended.
yes
words are only hyphenated when they have a separate meaning when separated than they do when hyphenated
The word well-being is 2 words, usually hyphenated.
All-consuming is hyphenated
No, "homework" shouldn't be hyphenated.
Yes it should be hyphenated.
No. Well above is not hyphenated.
No, well above average is not hyphenated.
Well-to-do is a hyphenated word. The direction west-northwest is hyphenated.
It should be hyphenated.
Yes it is, if it precedes the noun, as in "a well-known actress." If it follows the noun, as in "the actress is well known," it is not hyphenated.
To-night At a certain moment in time "well-come" used to be hyphenated.
well-meant
Yes
"Custom-built" is typically hyphenated when used as an adjective before a noun, such as "custom-built furniture."
well-known
bond