Yes it is ok to gamble with bitcoin.

I think there are definitely a lot of scams out there, but people should be wary. You really should not spend money you do not have, and treat it as entertainment rather than a job. Also even with gambling you should read up as much as possible and have proper money management with adequate capital, so even if you have 20% scams you have gambled on, the other 80% will more than make up for losses.