Of course, only the market can decide if finally the initial project known as BitCoin becomes money, but the initial objective of the project was to provide an anonymous and decentralized medium of exchange and store of value (i.e. money), or at least I have no knowledge about any other non-monetary objectives. Anonymous and decentralized are very nice characteristics, but they are specific characteristics that were specifically designed for its purpose as a medium of exchange
Still the first transactions can be viewed as bartering in a new commodity. That someone wanted to have because of it's unique value that you can enforce your property right in it very easily and without anyone knowing who you are or just because someone was thought it was nerdy fun. Either way it would fullfill the regression theorem.
Payment implies exchange, money is medium of exchange. BitCoin is not VISA (payment service), they are exchanged for goods. The payment is performed through the delivery of BitCoins in exchange of goods and services.
It doesn´t matter where you place your ask order if it is not filled. Bid and Ask orders are subjective valuations, price arises from real exchange (executed transactions).
But the way BitCoins are held and exchanged adds alot of value on top of what would just be expect to get from it as a medium of exchange. This is separate utility built into the system. BitCoins exchangability and the way they are owned and exchanged are different things. Even if you put everyone with bitcoin on an island so they can all still meet eachother easily they probably would not use it if they had to carry it on them and trade face to face, so there is some other value there that makes people want to hold and use it.
Credit currencies are currencies because of its monetary utilities other than store of value (in fact that´s their weakest utility as currency). The great difference between money and credit currency is that the first is a present good used as currency, and the second is someone else's liability used as currency.
Yes, and when the liability is issued it's value is specified in something else that has a price. It can be fraudulent or debased after but that doesn't matter for the regression theorem since such action will only affect the future price of the credit currency thru normal laws of supply and demand. I still don't see how credit currency has anything to do with invalidating the regression theorem.