So, as Vorpal pointed out, I evidently can't read.
I still disagree with you about regeneration, but I think it's just a weird thing in my brain, probably the part about reattaching limbs that just makes the machinery up there go "TILT." Looking over fast healing, I don't see the problem with swapping it out (I mean, it just kinda bothers me that immortality would mean resistance to one kind of damage [slashing] and not another [fire].) The Immortal Fighter of Doom laughs as you cut him, but brandish a torch and he squeals like a little girl and runs away? Eh, I'll shut up now, since I don't see either of us budging the other, and we'll just have to agree to disagree on the point. If I ever use your template, I'll swap regeneration out for Fast Healing, free Diehard feat, and immunity to death effects and massive damage, OK?
Originally Posted by The Vorpal Tribble
"Eternal Youth (Ex): An immortal creature does not age but remains at their adult physical peak. They take no ability score penalties for aging and cannot be magically aged."
And I know I'm being stupidly picky, but you don't say anything about preventing death. I guess it's a moot point since the Monk class ability (Timeless Body, I think) has to specifically mention that you still die of old age as normal, but I like things like that to spelled out explicity (evidently there's a bit too much of a rules lawyer in me).
Don't even know what Highlander is
Eh, a movie that got turned into a TV show my mother liked for some reason. It featured immortal humans who could only be killed by decapitation. Other normally fatal injuries just made them appear dead for an apparently random amount of time (ranging from a couple of hours to a few days, though it seemed that the more you "died" the faster your recovery time was). At which point they'd be back. Of course, that would be an acquired template, since an immortal was perfectly normal in every respect until their first "death". That's the point at which their aging halts (there was one episode that concerned someone who underwent this process as a child, and used that to his advantage).
Heroes Chronicles was a game, and well, if you died you lost, so Tarnum mainly avoided death by being good at what he did. (Again, his immortality was acquired, forced him by the Gods as penance.)