Uhm... oxygen is what causes aging. I'm almost positive if we found a way to remove that, we'd die faster.
I would like to live longer than 15000 years. I'll go for 3k if I can.
It would probably be the same like you said now -- assume the average is 14000, and the further you are from that, the more tragic it is. Theoretically, people could live that long anyway except that oxygen thing. The proportions would be different I guess.
I'm guessing people would kill themselves much faster -- drinkers, smokers... I think that 1% thing would go way the fuck up once a few of these chain smokers got to be 110 or so. Same with exposure to driving. Statistically, the more exposure you have, the more likely it is you'll have an accident. The entire equation changes once people can live forever.
Presumably, war wouldn't be a problem, or at least not a big one anyway, because somehow, I don't think we're going to have much of a good shot of colonizing other planets if we've not got an, at least *mostly* peaceful world down here on earth. There would be a lot of thwarting of other nation's effort and such otherwise.
But you might say "if and when we run into extra terrestrials there'll be a war." No there won't. If they're curious enough to be colonizing planets too, they'll want to study us more than they'll want to kill us. Think about it -- if the scientists of earth would rather study things for advancement of technology and understanding, why would they be any different? Seems like curiosity would beat out fear. Chances are, they'd only attack, if they felt threatened -- maybe not... I don't really know, but I don't think they'd be smart enough to build a ship, but dumb enough to think they need to kill all other ships that came near with no reason.
"But nocapszy, wut if we travel to the home planet of another race and they haven't learned about space travel yet?" Well, chances are, if they're going to attack us, but didn't have space weaponry we could:
B. Beat them
Seems like a win win.
So war isn't a problem. It's not a *major concern* At least not until we run into another goliath intergalactic force and start squabbling over planets. At that point, I'd make sure I was dead, because I'd be too embarrassed show my face as one of the races who does that bullshit.
The trick is to cut and run. Compromise. That way, we don't lose our civilians and soldiers -- and subsequently our reason for colonizing in the first place LOL -- trying to take something from another force that they could easily snatch back up in a year or two.
So, I'm going to assume that we've lucked out, and gotten diplomats smart enough to know how to handle these things.
At this point, we can only destroy ourselves. And boy is that easy folks. Alcohol and cigarettes. Expeditions gone wrong. Car wrecks, that one's been mentioned. Rate of exposure goes up and statistically you're more likely to have a fatal wreck as the years go by -- granted it's not a guarantee, but it does become likely.
I think the real causes of death will be those things that take a very very long time to kill us. Like McDonalds. And smoking, like I've said. McDonalds will be the biggest threat to all humans in this world.