not really.
Of course I am! Apple are actively promoting that you give a family member or friend your old iPhone. Therefore, if the iPhone is still under warranty (as it is), I am now one of Apple's customers. I am already, I have lots of Apple products, and have always been a fan of them.
So your buddy sold you a defective iPhone? Sounds like he should be the one you're mad at.
Yes, you can put it that way. He told me that he will give me my money back if i cannot get it sorted.