There's really no use of casino cash unless your using it for the games inside, giving it out to other people, or I remember there's a "Buy your own event" where you can set what event you want and you control that event for 1 hour. Other than the buy your own event, cc is pretty much worthless.
To get more Casino cash:
*Bounties, people may do bounties and if you kill someone you maybe rewarded a specific amount.
*Recruiting contest, most of my cc are from recruiting contest I got back then. There would be 1st, 2nd, 3rd place and there's an amount you get.
*Posting on forums, I think you get 100cc posting in the forums.