Interesting. I would add some betting limit so that a Whale doesn't break the bank, although I don't know if they all do it by default.
Most of them have around a $10000 betting limit and maximum winning caps in 5 digits for each cryptocurrency. The issues come when the casinos only have a backroll in 6 digits, or even worse, in 5 digits only.
At minimum you need $1 million dollars inside your bankroll at all times (sites with thousands of active users should have at least $10 million) , whether it comes from investors, or old coins which have suddenly become valuable.