It's a standard phrasing: "Store of value and medium of exchange". But for me it sounds like "animals and dogs". Because for something to be a medium of exchange it have to be a store of value as well. Medium of exchange is just a short-term store of value.
Wouldn't it be more correct to say just "store of value" (short-and-long-term)?
I agree with you. The store of value is the prime function of money. This function also makes sure that the value is more than the use-value of the money stuff itself. For bitcoin, all value is money value, which is perfect because the hoarding of money therefore does not distort the production and consumption decisions.
This is important for the question of the scalability of bitcoin. Should there in the future not be enough capacity in the blockchain for all wanted transactions, only the large transactions will be conducted on the blockchain, and the function of bitcoin as a store of value will not be harmed.
The third function traditionally mentioned, the unit of account, well I don't give much attention to that. There is nothing that has a fixed value, so nothing can be a definite unit of account. That goes for dollars also. To calculate if a trade is profitable, you have to take into account that your chosen unit of account is not accurate. You can invent an index of adjustment based on your own values for that. Basically, you can not compute it exactly, you must apply your own valuations.