Any that your suggested are better fit in my view. However, its not in what word is used, but how they define this word. And they define it this way: "FASTNEXT defines what is inappropriate". In other words, FastNext decides what's good and bad for them, at their own discretion and at any time. And sometimes, you don't even get a note to correct it.

The points described further in the TOS do not necessary define this particular clause. They don't say "here is what we mean by inappropriate". They just inform you that there are inappropriate things which they will decide on themselves.