There are many other controversies that have developed to date.
At the FIFA congress which was held in Doha, last March, there were protests at the congress, one of which was the president of the Norwegian Football Federation, in addition, protests were also present from football players, one of which was a football legend from Bayern Munich, Phillip lahm.
however, despite the controversies. I think it's hard to imagine Qatar trying to buy a referee, as you said, I'm always optimistic and positive thinking that things like that don't happen as long as this tournament goes on until the end.
I don't think that Qatar would try anything like this. Already there is a lot of controversy regarding the issue of laborer deaths and LGBT rights. They definitely don't want anything new. Also, Qatar is participating in the FIFA world cup for the first time. That itself is a big achievement for them (although they qualified automatically as the host and not through AFC qualifiers). I guess if they manage one draw against either Ecuador or Senegal, the Qataris should be very happy. But in all probability, they will finish at the bottom of Group A.