The P2P lending feature is great, but needs some fine tuning. Apparently it is possible to borrow very short term (minutes, hours?) and not pay any interest at all. This feature is being actively abused by some borrowers. Lending offers are taken, and the borrower returns the money immediately. There are various reasons why the borrower would do this. The wildest one being; one could set up a borrowing bot to constantly recycle loans, and thereby borrow without paying any interest at all! For a lender, choosing "Auto-renew" is not always a good option.
What would be the purpose of such a bot? I don't see how it could be used usefully. I mean margin trading costs fees and they are high on bitfinex. So i wonder where you see the problem.