Word Entry- "On My First Son"

1.  "Will man lament the state he should envy" (624)
2. I think it means holding on to something that he will never get back. The poem is about the death of the authors' son.
3. Definition: to feel or express sorrow of regret (Dictionary.com)
4. My guess was right! The author, Ben Jonson,  is trying to express that he regrets the death of his child. He wished his soon was still alive.