The Nymph's Reply to the Shepherd Immortality Quotes

How we cite our quotes: (Line)

Quote #1

If all the world and love were young,
And truth in every Shepherd's tongue, (1-2)

This opening line reels readers in by raising some immediate questions. What would be different if all the world and love were young? What lies has the shepherd been telling, and how do they relate to the youthful, love-struck world described above?

Quote #2

But could youth last, and love still breed,
Had joys no date, nor age no need, (21-22)

How would your life be different if your joys had no date and you had no need to plan for your future? Is it even worth mentioning, since this is pretty much an impossibility?

Quote #3

But could youth last, and love still breed,
Had joys no date, nor age no need,
Then these delights my mind might move
To live with thee, and be thy love. (21-24)

Are immortality and endless happiness the "delights" being referred to here? Or is the nymph referring back to those pesky caps and kirtles?