Cat's don't normally bite their toys. They like to toss it around and chase. When they bite, they are aggressive and it means they're not comfortable with the toy.I think your cat just views it as a toy. Maybe your cat needs some toys to play with you can work on that.
That's true. They don't talk so the only way is to show the act through aggression. It's best to listen and observe, changing the brush will be the first thing.It's a message for you to stop. It's not about marking territory, she's just warning you to stop. You can try another brush if it's same thing.
Even though they don't talk like human being there is a way they communicate through meowing and hissing. If your cat is constantly hissing, it means that they are not happy about one particular thing.That's true. They don't talk so the only way is to show the act through aggression. It's best to listen and observe, changing the brush will be the first thing.