i think they are called trukulus finguli.... but im not sure
no!
A human has 10 fingers; all thumbs are fingers but not all fingers are thumbs.
Not usually, though on very rare occasions it has been reported to happen. My left index finger was cut off at the first joint when I was about 2 1/2 years old, by my estimate, in a door. It was...
8 fingers 2 thumbs