This forum is enough for me to determine if a gambling site is legit or scam. Many users will help you here to avoid useless gamble sites. They can provide reviews and choose from different kind of games like casino, sports betting, dice, lottery and or combinations of them.
Yes if bitcointalk community is not supporting the fight against scams, I could not have got any legit gambling sites. Making use of this forum will be more than enough to identify the legitimate of any programs/sites. In many occasions bitocintalk helped to win the disputes too.
start with a small amount and if everything goes well, you are safe to go big. But then gamble only what you can afford to lose as you never know a site is good one day and scam the other day.
If you keep testing site with your money, probably you may end up losing big money summed up over time. It is always a good practice to read reviews even before going for testing.