What is a good thesis topic for Zora Neale Hurston which is not based specifically on any of her books?

One of the most interesting things I have always remembered about Zora Neal Hurston is something very bold which she did--both as a woman and as an African-American. 

She was writing during the Harlem Renaissance in America, a time in which African-American writers, artists, and musicians were coming into prominence, really for the first time in this country. Finally this ethnic group had a voice, and the majority of African-Americans felt that these opportunities should be spent promoting the black cause, so to speak. In other words, the writing, art, and music of the Harlem Renaissance should only portray the great strength and dignity, among other things, of this group of people, If not these things, then they should certainly reflect the historical oppression of African-Americans in America.

Zora Neal Hurston did not get--or at least did not heed--this figurative memo. She knew and loved her people, but she characterized them honestly. Any of their cultural bad habits, character flaws, or faulty thinking showed up in the characters she created. They were written with a gentle, even loving honesty which is admired today; however, her work was not well received by the African-American community at the time. They condemned her for putting their flaws on display as well as for not using her "voice" to promote the black cause or criticize black oppression.

We see examples of this characterization in Hurston's most acclaimed novel, Their Eyes Were Watching God. Janie is not like the others of her race who she sees as being too often complacent, lazy, and downright nosy about other people's business. When she arrives back in Eatonville after leaving in a bit of a scandal, she says this about her fellow citizens:

“Ah know all dem sitters-and-talkers worry they guts into fiddle strings till dey find out whut we been talkin' 'bout. 

Janie knows that the people in Eatonville love nothing more than gossiping about other people, especially people who dare to do something productive and different with their lives. Hurston says about them:

Seeing the woman as she was made them remember the envy they had stored up from other times. so they chewed up the back parts of their minds and swallowed with relish. They made burning statements with questions, and killing tools out of laughs. It was mass cruelty. A mood come alive. Words walking without masters; walking altogether like harmony in a song.

Finally, Hurston gently condemns her fellow citizens for wanting bad things to happen to Janie, a woman who simply wanted to follow her happiness:

“An envious heart makes a treacherous ear. They done 'heard' bout you just what they hope done happened.” 

it has always struck me as being a bold and courageous move for Hurston to write authentically about what she knew, despite the backlash she received from her own people for doing so. I am certain you could find this attribute in all of her writing if you need more examples to make your case. I know you will find all kinds of commentary on this issue, as well, since it was quite an uproar for many years.