I think you should do a thorough research about a casino before you throwing your money into them, not even single dime. There are also a lot of other functional and trustworthy online casinos which is also tested with lots of positive remarks that you can try with also lots of bonuses and incitives.
One thing you should know is that, everyone is not the same and no one should be trusted on this internet space a d you should try searching for reputable casinos in the forum.
Not to mention, there are tons of sportsbook websites out there that are far more reputable and trustworthy. Though I am not completely dismissing OP's question of that website, but there are tons available that are well-received by this community.
Like what you mentioned, you are correct for doing the research in this forum first before putting any money. Again, prevention is better than cure and it is very wise for you to ask for feedback in the community before delving completely on it.
And if many of us don't know about the sportsbook website, it means that the sportsbook site is not well known in this forum and you need to be careful if you still want to use it for gambling. This forum has many trusted sportsbook sites that you can choose one by one and try to play so you can find the one that suits you. Don't take the risk of playing on a site you don't know because it could trick you later. You can get a sportsbook site from this forum so you don't have to look for the site through a search engine.