RE number 5, you seem to be mistaken. Those random loans were all repeat borrowers. "I calculated the APRs for these 20 random Zidisha loans, and the average APR for the loans was 25.22%. The Zidisha APRs for these 20 random loans went as high as 49%"..."And that's just for repeat borrowers (by sheer chance, none of the 20 random loans was from a first-time borrower)."
That said this looks like an awesome response. I think you're net good, but I know what happens down the revolving credit pothole, if you're helping people avoid that its fantastic.
One other concern, your fee structure and business model seem to encourage repeat loans, how do you avoid the situation where that goes horribly wrong?