But that is not really a concern for any of these merchants, as they don't store bitcoins anyway when BitPay is used as BTC payment processor.
Hard Fork split wont happen bitcoin community and developers won't ever allow that. It would undermine bitcoin's position greatly, miners are aware of that.
Merchants needs to realize that bitcoin wallet is a good way for easy transferring of money and it will helps them alot to ensures the payment. It will also help knowing that bitcoin value is rapidly increasing. They can save enough and can use transactions monitoring.
Yes, but they need to wait when the price of bitcoin decreases. The price of bitcoin decreases they won't get the actual value of the product, so in this case, shop keeper's will be in loss, so it will be very hard to convince the local business people.