Are the Finches racist?
Technically, I suppose so, if you look at it as a yes/no question. Scout seems to have absorbed some of the language used by the citizens of Maycomb, and traces of the attitudes.
However, if you look at them in context, they are very much opposed to racism, and the novel is very much about people learning to see past socially imposed boundaries (including race) and seeing one another as they. Atticus leads a very public battle against racism.
I do not believe the Finches are racist, they simple have picked up the language customary to their time period. Atticus opposes Scout's language, and he is defending an African-American in court. Because of this he is scorned in the county of Maycomb, because "racism" was customary in that time period.