Good luck with running your own casino but I will make a few suggestions that might help you.

1. Be cautious and avoid instant withdrawals initially because a new site always have some bugs and abusers can wipe the entire balance out in a few hours.

2. If you want to have a sportsbook you will need a odds provider such as sportsradar I think.

3. Instead of spending money on welcome bonus, focus on paying more to the people who deserve. Like give them more weekly, monthly bonuses.

4. Might as well start your own casino token because that solves your liquidity issues to some extent.