Making a forever living human would be powergaming and breaks roleplay. Its hard to get everything right though. I would support having an auto-aging part. Elf- 20 years old Human- 20 years old; *many, many, many years later* Elf- 1749 years old Human- 20 years old. I say no to that happening.
If it eventually leads to a character to be obliged die permanently, then no. People can choose how they age their characters if they want. When elves properly RP their infertility, and not as a race of females who marry and live with humans, maybe then I'd support it.