I think the aging question and the genetic solution offered for it would be the basis for an excellent Power for 2e skills and powers or a Feat for 3e:
d'Ambreville Blood aka Child in Amber
by Alfred O'MeagherRequirements: Wisdom OR Constitution OR Intelligence of 15 or more, can only be chosen at time of character creation; may only be selected by a player whose character is human or of a race that can successfully interbreed with humans
[Although not restricted to scions of the noble house of d'Ambreville itself, this power of the bloodlines of Old Earth is often named such simply for convenience.]
You are a descendent of an alien bloodline of wizards, witches, . This means that your metabolic rate is different from that of a normal human and as a consequence you age 5 times slower than a normal human. Additionally, when choosing to prestige class or multiclass in a magic-using or monstrous class, ONE prerequisite of the prestige class or true class that you wish to change to may be ignored, to reflect the alien powers of your bloodline.
Those people possessed of this type of bloodline are frequently hunted by Blood Mages, Blackguards and evil Necromancers, who wish to win from the character the secrets of their alien genetic potential or simply sacrifice the character to their Dark Gods.