I really like your "bankroll as a service" idea. I think that unbundling bitcoin casinos is the way forwards. Right now many operators do everything (game dev, banking, security, marketing) themselves. Would be rad if people would specialize on the components bc that could improve the overall customer experience, and at the same time make it easier to build a bitcoin casino.
Unbundling is definitely one way this industry can evolve. Imagine if we could pool all the investments together across any of the sites that are willing to partner up..
The only thing with Vault is how do you trust your partner operator to be "provably fair to investors"?