Well, I don't know. I think the possible pain preceding death could be endured in that your mind would be more ocupied with the thought of not thinking. I don't believe there will be anything after dying. I don't believe I'll be able to perceive, so I'm not all that worried.
As to immortality, the greeks/romans felt that the gods were jealous of us. Mortality makes every facet of life more beatiful. Because we can die, life is worth living, and makes everything worth while.
As to a set time for death; if you'd like to know yours, visit Death Clock
List of things to do before death:
1) Accidentaly slip on banana peel
2) Slap someone so hard their neck brakes
3) Have my hands behind my back, and have to break a guy's nose with my forehead; cause he's talkin' some smack or something. Then the enemy leader with whom I emotionaly connect, but do not share political/religious ideals makes him not kick my ass, because he knows I'm a bad-ass.
4) Nonchalantly fight someone. Like it's nothing. You know, like while I'm writing a letter or something, with my right hand, and fighting ninja's with my left.