Hey, anything can be a PC if the DM allows... however, it also needs LA for cohort and stuff.so, this template would be usable for a PC? seeing as how you added the LA in there... It would be insane, but some people might like it
Under skills:One thing I would think though, bonuses to Knowledge (History). Either in "Been There, Done That". There is a chance that if they are an immortal that they could have been there for a historical event.
"An immortal gains a +10 bonus to Balance and Knowledge (history) checks. "