Your bankroll should be high, but that depends on what your bankroll is, if you have only 10 btc, you would have to make the max profit of your casino something around 0.1 to be safe, so it depends on your bankroll. If you want other tips, have a faucet for your site, do a few giveaways and people will come to your site
Faucets and giveaways bring people to your site but they are not the people that are going to make the site a profitable site. You are right about the bankroll you will have to know what your own bankroll is to then know what to keep the casino max profit at so you can always pay your winners.
I am really not sure if you need a license because the legally grey area, I would go with no with bitcoin casino's you don't need a license but 100% you will in future so would probably be best to start with one imo and be different to all the others
I have a tip and that is you need to be able to fund a big advertising push once your site is live and working with nice deposit bonuses to attract the right players.
Thank you very much for the reply sir. Casino licenses in countries like Panama cost $60k/year AFAIK. In countries like US and all, its way more than that.