They're allowed now. Just no Fanfic battles, no deliberate spite threads, no Superman Family vs Goku Family of any sort, and no battles without at least 1 anime/manga character present. There are other rules but I'd say those are the most important. And I agree with your analysis, although, Thor is immensely fast when he needs to be, he usually can afford to rely on merely his immense brawn and durability. Also, while the Kings are incapable of killing Thor, I wouldn't say complete non factors if Thor were in character. But bloodlusted yeah they are pretty much dead.