The Namesake is actually a novel not a movie. Not a difficult text to pick up concepts of belonging. And there are millions of related texts you can use that with this.
Possibly. This is why I really don't like to share essays. But the markers have to take into account the fact that the people are in the same class as you, so the teacher will teach the same stuff, give same notes etc.
I don't think they're that good. Better off learning more "detailed" stuff from a reputable textbook such as biology in focus/context etc. I would use them just for 'leisure' reading, as in just to skim read what you already know.