Morphene (Med-X), booze, PCP (Psycho), steroids (Buffout), speed (Jet). RadAway comes in an IV bag. Rad-X comes in pill form. Stimpacks in an automated syrette.
Drugs have a chance to cause your character to become addicted. Like alcohol, this can be treated by visiting a doctor or getting a medical table for your house.
there is a perk you can select that allows your character to eat human meat. There also is a side quest with cannibals involved, and another one with vampires who drinks human blood.
There is an option in the main quest that ends up having someone sacrifice themselves if you don't take steps to avoid it detailed below.
[SPOILERS]
Before the end of the game (starting the purifier) you need a companion resistant to radiation such as Charon or Fawkes to avoid someone having to sacrifice themselves.
- the player has to crawl through a narrow pipe in the jefferson memorial, in order to activate a valve - vault 87 contains several tight corridors with enemies and low lighting, and can only be accessed through an underground cave
both are required in order to progress the main story
(SPOILERS) There is a suicidal man in Rivot City, who the player can optionally convince/aid in helping to commit suicide. The player also has the option to help the man. Beyond this, no.
Depends on wether or not you have the Broken Steel DLC. If you don't, the protagonist dies fixing the Water Purifier due to the radiation in the chamber. If you do, it's retconned into only being rendered comatose by it.