two more points. Very nearly every bitcoin mining operation not only sells their mined coin, they do so nearly immediately (to pay electricity and other production costs).

That is to say that nearly every bitcoin that comes into existence right now is immediately sold on the open market. And theyre almost always priced to move at or near market price.

Though it is not that difficult to transfer STEEM to Bittrex or some other trading site and convert it into Bitcoin or some other currency, it still means that there is a process to go through, and a middle man. If STEEM required no middle man, then it would increase the ease with which it could be used, and I believe that would increase the value as well.

You realize that when you use your shift card, you're actually selling the bitcoin, not holding it, right.

That is to say, lets say there is a steem visa card. You go buy a $4 latte with your steem visa card. Whats really happening is that the card issuer is paying $4 in cash to the coffee place, and sellilng $4 worth of your steem on an exchange at current market prices to pay themselves back.