The example you provided doesn't just occur without serious distortions elsewhere in the system (internal, external or a combination). But yes, without tracking every transaction and the rationale, it becomes increasingly difficult to manage the money supply.

In the current system, banks provide credit and came to treat debt as money, but they do not increase the monetary base. Ironically, if the banks did print their own money, the ongoing financial crisis probably wouldn't be as pronounced although other issues would arise.

I would agree that speculation on expanding economic development can be categorized as demand. The question is whether we're talking about a hypothetical system such as one predominantly based on Alt/Bitcoin or the current system.

In the current system, speculation builds on itself because there are no consequences for being wrong if the speculator is a major player or otherwise in a position to be bailed out. In a Bitcoin-based system, there is no way to manipulate the monetary base, so a speculator who is wrong will have to take his losses.