Liam is shown drinking several times through the movie as a means to cope and it's implied he used to abuse alcohol (the hidden bottles; almost every memory of him involves drinking.).
No, but in order to demonstrate the effect of the "radius", the main character intentionally experiments with or uses animals (birds, a goat) that he knows will be killed. The deaths are portrayed as instant and seemingly painless.
Rose or Jane (The same person) describes a flashback too Liam when she was 7-8 that she remembers. She said that a kid at the mall removed santas beard. Giving the impression of that Santa is not real.