Discrimination is when you treat someone in a disrespectful manner based on their age, sex, race, etc.
Age discrimination is when you disrespect someone based on their age.
For example, a cashier follows a teenager around the store because they believe they are going to steal something since they're young and naive. Or, not letting an elder in to a club because they're too old to dance.
The true meaning of the word "benign" in this sentence is - harmless. It is the word that originates from Latin word "benignus". In medical terms, it refers to something that does not cause death or serious injury. Also, it is most commonly used to describe tumors which are not cancerous. The famous American film director once said: "The most beautiful words in English are not 'I love you' but 'It-s benign'." This word can also be used to describe one's character, meaning that he or she is kind, gentle and that can hardly harm anyone.
I am not sure which poem you are referring to here, but one poetical technique is called enjambment. This occurs when a line continues to the next line without a pause. Even if there is a stanza break in between, the lines are meant to be read continuously. For example, consider these lines from a poem by William Wordsworth called Beauteous Evening:
"The holy time is quiet as a Nun
Breathless with adoration; the broad sun
Is sinking down in its tranquility"
Here, Wordsworth is not intending that you pause after you read "Nun" or "sun." He wants you to read these lines as a continuous sentence or thought. Hope this helps.