If sportbet.io covers the matches you are looking to bet on, then you should settle with them because they are one of the best sportsbooks we have here in the bitcoin community. There are others as well which allow betting on sports with bitcoin, but sportsbet.io are still ahead by significant margin.
Do they have english site? Because when I open that I can see only chinese characters everywhere.
I have heard there are players who were taking advantage of the wrong odds and things like that [...] so they can just cheat
Actually in my opinion this the betting about - to find wrong odds and have advantage over the bookmaker. This is called "value", when the odds are i.e. 1.8 and real odds should be 1.3-1.4. You can win if you have more information about specific team or match than the bookmaker has. What is the cheating here? Even if the bookmaker has 4.0 odds and the real are 1.8 then also how can you name anyone cheater if he want's to get an opportunity of that? Of course sometimes the odds are wrong by mistake and then bookmaker can void the bet.
I don't know your betting experience but that's why I don't bet on mainstream markets in sports or esports. The odds are properly adjusted to the risk and in long term you won't win with the bookmaker. Lower tier matches aren't so popular and also trader don't have enough resources to give the right odds.