As to your B statement. The security is that I have a mass mining op (in the 10's of ghz) running for my own use and can cover any loss of contract I accept. I can and will deny orders that are to rich for my blood.
Excellent, and I think a Bitcoin credit market would be a very useful thing indeed. So how does an investor lien the mining hardware in the event of default? That is to say, if I want to give you 100 BTC as an investment (amount can be anything) and you just never visited the forum again, what can I do as an investor?
I guess this question belongs on the trading forum but a traditional company will have a legal records address where I can (in theory) sue you if you fail to pay.