Its not even legal tender so the merchant would have to convert back to fiat anyways. If they need fiat to operate their business
The easiest way to do this is through a service similar to credit or debit cards. Isn't there some service for this already?
Its a pain to use bitcoins currency. No different if you work for dollars then instead of a checking account you buy gold. When you need dollars you sell that gold back to dollars to make purchases
Right but the goal of bitcoin is to be a global currency, not a commodity. It will never see widespread adoption if the consumer has to worry about tracking the price a BTC was bought for vs the price it is selling for when he goes to use said BTC in a transaction with a merchant. Imagine if every time you spent a dollar, you might be liable for capital gains tax because that dollar increased in value since you acquired it. It's not feasible.