There is no such thing as assisted suicide. It is an oxymoron and a fig-leaf phrase designed to assuage the guilt of the killer, like "pro-choice".
If you want to call it consensual homicide, fine, but don't pretend that the real killer in the situation is in any way committing a "suicide". They are killing someone else, plain and simple.
Not necessarily. Many assisted suicides are conducted with a doctor setting up a lethal drug delivery system, that the patient has requested but is unable to arrange without the doctor's help, and then leaving the patient to actually self-administer the drug. However, in cases where the patient is so far gone as to be unable to operate a drug self-administration system, then if the patient has clearly requested it, there should be no obstacle to the doctor carrying out the patient's request.