I absolutely agree that you should get rid of that red warning. It is both pointless and unenforceable and would be enough to make some buyers think "Let's see what Paypal think of that rubbish"

Why would you want to give buyers even a hint that they can go without paying? You would do much better if all your statements were positive.  Perhaps you should read up on the psychology of selling, if you google it you can garner some very good advice on how to persuade buyers to buy from you.