Goodluck with your project. 
Yes, good luck! The vendor, if they are honest, is going to be having a battle with Visa, Mastercard, etc every time there's a claim by a dishonest buyer that no good or services were received from the vendor. It will be interesting to see how this plays out. It might even make new precedent, or at least end up in Yahoo News!
Yes, this has been on my mind since I started this a couple weeks ago. I have been keeping meticulous records of Bitcoin addresses and TX ID numbers when shipment is made. When a chargeback comes in, I have a set amount of time to respond and defend myself and a payment is not just automatically taken from me. So far, my customers have been happy and most of my business has been repeat business