I was there with 2 ten-year-olds yesterday, one had to cover his eyes for the inferi (which were bit nightmarish really), the other was fine. The death was saddish but ok, I don't think any of us were very affected tbh, and we were v sad when reading it.
Greyback is really evil in the books, agree he was not the worst horror in the film. HB-C was unpleasant and I found her strangely sort of sexual, all breathy and bee-stung and tongue-tippy.