i dont have one as i only care if its a gambling game or not i really like to spend my time playing gambling games as it gives me a lot of entertainment
i dont think so, the owners put in some hard work usually in creating these games so they earn money for their work and its their decision to either donate or not
if i were in your shoes i wouldnt invest my bitcoins and keep it in either my paper wallet or hardware wallet as the price of it will start growing after some time
i highly doubt that there are any of such things created as it would be way too easy to win and beat the house edge what would bring a lot of money to you