Although this is more for things omitted. While, as I said, I didn't miss the Skrewts, I did miss the whole giants thing. There was no reason given why Hagrid and Madame Maxime were unusually tall, or as someone else said, that giants even existed. (Hey, means no Grawp in the next movie! That *is* a plus.)
However, those two items are tied together. The Skrewts were not only unpleasant and dangerous, they were also illegal. Why? Because they were crossbreeds. Hagrid wanted to see what would happen if he bred a manticore with a fire-crab (thank you, HP Lexicon!).
All well and good when dealing with, er, "interestin' creatures", but. Hagrid's also a crossbreed. In fact, there seems to be a major prejudice against semi-human intelligent races, such as merfolk and centaurs. I think werewolves also count as that, although I'm not certain.
That leads me to think about half-bloods. If you don't consider Muggles to be equal to wizards, and it's clear that even the Weasleys aren't sure (although they don't seem to have that problem about nonpurebloods, blood traitors that they are), then half-bloods and Muggleborns are problematic, even if the majority of wizards are, in fact, half-bloods. Which they'd have to be, given the small size of the population. It's why the Gaunts are so inbred - they didn't trust anyone else. One wonders about the Malfoys and the Blacks - I've been fairly certain that Mrs. Black's maiden name was also Black.
But none of that occured in the movie. I understand why - it's not necessary to the plot, not really - but still.