First of, I don't think that reputable rating/review sites can be paid to show fake ratings, because if caught doing so they would lost their audience immediately. Speaking about the red flags, if site is a very new one and there are no reviews about it yet, that's the red flag number one for me. I never deposit on such sites whatever deposit bonuses they promise.
Overall I suggest to trust the sites with good reviews and operating for a relatively long time. On those sites you can deposit without worries, they won't scam you. But of course you should never deposit more than you can afford to lose because even on a legit provably fair site you can lose money to gambling.