G(x)=x[x+7]
Even
Odd
Neither

Well, one metaphor is the poem itself as a metaphor for a black man trying to make his way in a white world and the ways that both are changed by it. Consonance is like alliteration but at the end of the word instead of the beginning. Light, slate, and boat exhibit consonance on the "t."

I don't see any allusion here to other works, events, or anything. Although the list of cities could be alluding to being raised amongst a concentration of blacks since he next says he is the only colored person in his class now at Harlem.

Repetition is easy enough and look for repeating vowel sounds for assonance.