Corrected entry: When Chaz, Ari, Uzi, Royal, Margot, and Richie go to the cemetery to see Royal's mother's grave, they also go to see Chaz's wife. On the tombstone, the years read "1985-2000". That would mean that she died at the age of 15. When they show her in the slideshow earlier in the movie, you are able to see that she was older than 15 when she died.
Corrected entry: At the end Richie is hit in the right eye, but a bandage is later seen over his left eye.
Corrected entry: The seasons are terribly mixed up. At one point, it is winter, then you see Royal and Ethel walking in the park during spring, then Ethel is getting out of a cab in summer, after which, Royal is forced to leave the house and it's back to winter, complete with snow. Also at the end of the movie, the wedding is in the summer, but the final scene on the roof was obviously shot in late winter/early spring.
Corrected entry: When Richie is in Raleigh's bathroom, and he's cutting his hair you can see that it's not cut even all over. Also he's only shaved one small part of his scruffy face. When he is in the hospital recovery room with his family standing all around him his hair is all one length and his face is smooth like it was just freshly shaved.