#1: Answer: Who creates the bitcoins is irrelevant to the transmission and exchange functions. The special case of "creating and selling" is really a subcase of exchanging and probably was unnecessary to call out as it is already covered by other guidance. Regardless, it does not seem to apply to bitcoin miners unless they are in the business of selling their bitcoins for currency.
Miners who create currency and keep it or buy things are not covered in the guidance, as far as I can tell. A lot of your post seems confused by that issue and seems to be fishing for different definitions in order to understand how the act of creating the currency, by itself, is regulated. But it isn't. That is not the money transmission or exchange function that FinCen is interested in.
#2: Answer: If you don't sell the units to another person, then you are NOT covered by this clause: "a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter." BUT YOUR MAY BE COVERED BY OTHER CLAUSES.
Based on the following it does not seem like you are reading the entire guidance:
The "accepted" interpretation of FinCEN guidance is that anyone who exchanges virtual currency for real currency is an "exchanger" (unless an exception applies as defined by existing MSB & MT regulations).
However the actual text of the guidance
does NOT say that:
In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency.
You seem fixated on the definitions within the Decentralized Virtual Currency section. What about the definitions that are present elsewhere, like this one:
"An administrator or exchanger that (1) accepts and transmits a convertible virtual currency or (2) buys or sells convertible virtual currency for any reason is a money transmitter under FinCEN's regulations, unless a limitation to or exemption from the definition applies to the person."