When angry, my 2-year-old granddaughter clenches her teeth, bites or pinches. Are these normal behaviors?
My three kids all clawed and occasionally bit when angry as toddlers. One gritted his teeth. None pinched, but frankly I'd have preferred pinches to clawing. I'd say what you're describing is within the normal range.
At age 2, biting can be reduced a bit by making sure they have carrots and the like to chew on when teething.