Hyphens not needed
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 it should.
no hyphens - 57 years old is what you are.
No, you should not.
There are no hyphens in the word ago.
No. Use hyphens when creating a compound adjective, for example a two-foot width or a four-foot depth.
hyphens
I really doesn't matter, but if you're writing an essay or something, keep all words that can have hyphens, either wil hyphens or without them. My point is that you want to be consistent.
you should call customer support
— Just remember that when using hyphens, they are hyphens, not –, and – should be used for between times like this Come to Answers.com between 7 – 8 The Answer to the questions is "On-site"
You use hyphens to make compound words that are not recognizable in common usage.