That being said: You really really shouldn't start an exchange. Judging from your questions -- don't get me wrong, it's great that you are asking and trying to learn -- building and running an exchange is way beyond your current capabilities.
Thanks for reply.
Of course, I didn't started exchange myself alone. I am hired to company that preparing exchange.
Company has a lot of cash of course enough to launch exchange and so gathering specialists. (See my post at this forum's project section)