Our games have been rather lethal. We have been playing LOTFP for around two years now, usually thrice a month, and I have lost four characters. Two of them died, one started to turn into a naga and committed suicide, and one was trapped in a pocket dimension. I think I played for almost a year with the one who survived longest. On the other hand, one of my friends has only lost one character and that was mostly because the campaign was nearing its end and he decided to die with a style. So your gaming style matters a lot. I'm rather quick-tempered, so I just can't sit and watch the others do the job. On the other hand my friend is very patient guy and never as reckless as I am.
Also, our gaming style doesn't favour quick gaining of levels. Our GM is very stingy with treasure and I think we have never had a fourth-level character. Also we often spend several sessions with just role-playing out discussions, politics, and such. As you don't gain experience from killing, but from looting, HP is much more important than fighting skills, in my opinion. Monsters tend to be very tough and it's just better to survive and run. With the treasure, naturally. And that's why you need HP.
Also, what I have learned is that you definitely need to hire retainers. When you get the money, Charisma becomes perhaps the single most crucial stat. Gaining loyal NPC friends is extremely important.