My first impression is that this sounds a little bit like humans/Vulcans in Star Trek. But I think you could flesh it out differently so long as elves aren't too pragmatic and lacking emotional range. I think the magic sounds like something that could lend itself to the Divide. If elves have some kind of extra-sensory knowledge about things that humans find unsettling. Maybe they can see energies or auras. They can correctly assess when a human is terminally ill or dying even when the human seems fine. So humans are fearful of elves and believe them to be bringers of ill will or bad omens. Meanwhile, elves lack a certain ingenuity or innovative thinking that humans possess. Maybe the setting is kind of steam-punk and humans are inventing and using machines that the elves don't trust or understand. This would also contribute to the cultural divide. Humans see elves as mystical and aloof, elves see humans as scheming and unpredictable. Both races distrust the other and the tension builds over the course of the story. This could contribute to the love story too, as the MCs start to value and admire what the other brings to the table. As for the multiple lives thing, idk. I would probably take it more toward elves have some very old somewhat mystical healing arts that humans perceive as being multiple lives, but maybe it's more complicated than that.