Who is the speaker in the poem? Who would say this? Why would they say it? What are we able to infer about them? What is he or she like as a person? How do you know?

The speaker in the poem is a tenant appealing to his landlord. We know that he is a black man who is fed up with the way he is generally treated, both by his landlord and by society in general, for a number of reasons. First, the imagined "headline" at the end of the poem refers to a "negro." Second, the language of the poem uses African American vernacular, in phrases such as "'member" and "these steps is."
As a person, the speaker is obviously very brave—he seems to have been pushed to his breaking point by the mistreatment meted out to him by his landlord. He is addressing his landlord in this way because none of the issues he has pointed out, such as the broken steps or the leaking roof, have been fixed, and yet the landlord has continued to demand money. The speaker does not want to suffer like this any longer.
At the end of the poem, however, we can see that the speaker is sadly resigned to the fact that he probably won't be able to do anything about his, presumably white, landlord. The headline he imagines in the papers if he were to physically threaten the landlord have the tenant, rather than the landlord, in "county jail." The tenant is very frustrated because while he knows the landlord is in the wrong, he also knows that the system is corrupt and racist, and will work in the landlord's favor.