>> If I were to go to some hospital and found some person on life support and unplugged it, because they were inconveniencing me, would that be murder?
According to who? Legally, this has been the subject of debate because we just aren't sure how to define the end of life in situations we don't encounter often in nature. Normally all the body dies more or less at once. Someone who is brain dead is already gone, and I don't think you do any harm by letting the meat they left behind start to rot. However, it's illegal to kill any human that's been declared alive by a doctor, and not yet declared dead by one. I don't think it's murder though, merely acceptance.
>> What if they woke up but still had an air tube down there throat and I took a pair of scissors and shoved it into the back of the head and sucked their brains out, would that be murder?
A brain-dead person can't wake up because they're not in there anymore. But assuming they paradoxically do wake up and become aware again and you then kill them, it is murder, yes.
However you've made an obvious analogy to abortion, so you must want me to address that. There's a few problems with your analogy, which I have to point out first.
An unborn fetus is not in a coma. It was not ever declared to be a living human by a doctor. It is not brain-dead. It does not think. It is not aware. It does not have a soul yet. It is an empty vessel, waiting to be used. Neural development doesn't reach sentience or awareness for quite some time after birth. Usually several years pass before the infant realizes there is such a thing as itself, that it is unique among all the things of this world as being the one thing that is it. There is nothing in an unborn fetus to kill. That phenomenon grows later. If you've ever had kids, you might have noticed the first time their eyes seemed to light up with self-recognition.
(That said, please know I'm still anti-abortion except in cases of rape. That's because I believe in making people take responsibility for their actions, and against unnecessary medical procedures.)
