1: Capital to start of the busines because a casino need money to pay the first set of winnings that the casino is going to get because you can get hacked and the hackers get access to the code and manipulate it to favour their bets. New casinos are the targets of hackers looking for loophole and they find it most of the time hence you need to have enough capital to sponsor the casino before it starts generating money to do that by itself.
In the practical I think that the most important of all is this, the Capital , because Without capital we can not do anything, or we can not do much, because it is not just about making the casino with all its infrastructure and having only a capital there, it cannot be small, I have seen how some casinos that are relatively good , start with little capital hoping that with the clients they can capitalize and when profits occur for the players they leave the casino in a very bad way and that is when the problems begin, for me a casino when it starts is good when it has a lot of Capital and when they have enough for their marketing.