This is interesting, and i agree with most of the points (in a "ok, but lets see where it goes from here" kind of way).

Though I am not so sure about the concept of "hiding one's likelihood to die soon". After all, lots of people play the sympathy card with great social results (at least for a while, until it gets tired).

I suspect that having a friend that is dying isn't actually likely to cause a person to ostracise them... after all, it's a chance to show all your other friends how valuable you are by taking care of the sick friend.