If you are really serious about this and you have a large enough bankroll, I am taking about at least 100 BTC in cold storage somewhere.
Then you need to get custom coding done for a dice site. Don't buy any dice scripts because they all have bugs and many gamblers will find out what version you are using of a script and they will cheat you. Many dice scripts even have undocumented bugs so some smart hacker can just find some exploit themselves and later on go on your website and cheat you.
Your best bet is to hire a scripted coder who can build you one from scratch and you can also pay them a wage and they can maintain the server to make sure no new bugs arise.
However none of this will be cheap but its the only way you can run a dice site properly and gain enough reputation and trust.
This is easily one of the best suggestions on this thread to develop a safe and secure online casino, but there is one thing that you failed to mention.
There is always a possibility that the custom coder could himself/herself hack the casino whenever they want for obvious reasons which is why it would be wise to ask that person to submit his/her KYC which must be verified.
This would effectively prevent the coder from engaging in any wrong-doing in the future.
I understand however this is the reason why he needs to hire someone with a reputation to up-hold.
Most computer programmers who do free-lance work are usually not anonymous, they post their resume in public to get work. They are in the field of programming and not stealing money by hacking.
Usually before you hire someone, you look at their references, and if they decide to scam you, you can always contact their references and say they are dealing with a scammer and they won't get future work.
This is like hiring a lock-smith to change your locks in your house. Sure they can make a copy of the key and rob you in the future. However its very risky for them and they will get a bad reputation for doing so.
