also fair, but keep in mind the idea of him coming to rule them would probably be swiftly punted aside from the fact that he won't be staying and will be heading back to the kingdom after getting aid for the fight the the demons. A fight ill remind you the beastfolk have a stake in as well cause i doubt they want to be destroyed or enslaved by demons either.
Oh, this has nothing to do with Usato directly. It's the thoughts, wishes, and fears of the Beast folk/other people. Before Talk no Jutsu corrects all the misunderstandings, you have people who will jump to conclusions on their own, out of their own personal fears, or prejudices.
Worse than a Three's Company plot, you will always have misunderstandings that become amplified, because of the scale and size of the possible problems. For the LotR example, is Aragorn, here to save the human race, or is he here to take the throne of Gondor. Inquiring minds want to know, will imagine, and make shit up. It's in the nature of humans to "predict" future events. And since the story is written by a human, you can easily project that type of thinking onto other characters, human or not.