Can you combine Reborn with Dhampir? Both are "lineages" that combine with another race and keep certain things such as climbing speed (which dhampirs get), so could you have both or is there a rule I missed? I'm talking RAW, assume the DM won't smite the combo as I'm building for a very powergamey group.
No, one per customer
Per the rules of Creating Your Character:
At 1st level, you choose whether your character is a member of the human race or of one of the game’s fantastical races. Alternatively, you can choose one of the following lineages. If you choose a lineage, you might have once been a member of another race, but you aren’t any longer. You now possess only your lineage’s racial traits.