1. I haven't really taken responsibility for any society but the clans, so lifespan would vary depending on technology level, medicine, etc. For the clans I would say it is probably safe to say 50-70, though less for females on average because of the risk of dying in childbirth. The clans consider the age of adulthood to be 16 years old, and I believe this is more or less the standard (give or take a year, maybe) for this continent.2. A pair of 18 year old males are definitely men as far as clan society is concern. That is not to say that they necessarily feel like men, and men significantly older than they are (Cale, for instance) might still think of them as boys because he considers that he himself was a boy at that age.
3. Rites of passage I haven't invented; I would imagine that there aren't any (formal, anyway) for the coastal clans. The surviving desert clans, who are highly tradition-focused, might have ceremonies etc. associated which you may feel free to invent.
4. As mentioned in the naming conventions notes, females are given a small ceremony (close friends and family) wherein their father gives them their characteristic suffix as a signifier that the female is now old enough for marriage and therefore an appropriate target for the attention of men. However, in modern clans society (again, this may only apply to the coastal clans) it would be considered barbaric for a female to be married off before she reaches 16 years.
