It's unclear for much of the movie if the main character's injury (bee sting on his hand that swells, hardens, and then spreads up his arm like an infection) is visible to others or not, so could be read as unstable reality / hallucination.
About an hour into the film there's a scene with several teenage girls getting murdered, mostly offscreen, while another girl hides in a bathroom stall listening to it happen, including screaming.
Yes. Bees are present in most of the movie. There's also depiction of being stung by a bee, and the wound plays an important part in the movie later on.
Near the beginning, two characters are being attacked in an art gallery. One of these characters has their ankle broken and the audio of it happening is pretty loud
Near the end of the movie, the main guy is turned around from facing a wall. Half of his body is covered in holes similar to a hive and we see his arm closer up after his hand is cut off. He looks like this until the end.
There is a scene in an elevator. It can be seen as a rather suffocating scene, but that's just the point, since it's a scene that's supposed to be scary.
No. A girl with a shaved head dies, but there's nothing that really implies she's gay. There actually is a gay male couple in the film and they both survive.
Not sure if this is the right category for the comment, but I wanted to give a trypophobia warning for near the end of the movie. A character’s skin begins to appear with several small holes all over it.