
GM Enaris |

First, some context:
Bloodline Development: The arcanist selects one sorcerer bloodline upon taking this exploit. The arcanist gains that bloodline’s 1st-level bloodline power as though she were a 1st-level sorcerer...If the arcanist already has a bloodline (or gains one later), taking this exploit instead allows her arcanist levels to stack with the levels of the class that granted her access to the bloodline when determining the powers and abilities of her bloodline.
Eldritch Heritage
...Select one sorcerer bloodline...This bloodline cannot be a bloodline you already have. You gain the first-level bloodline power for the selected bloodline. For purposes of using that power, treat your sorcerer level as equal to your character level – 2, even if you have levels in sorcerer. You do not gain any of the other bloodline abilities.
So, yeah, how do these interact? If I select Eldritch Heritage (Abyssal), and later take Arcanist and select Bloodline Development, can I take Abyssal? Do I start getting the other bloodline abilities, since I already "have a bloodline"? I'm guessing not, that seems OP.
On a related note, I have an Arcanist/Fighter/Hellknight Signifer I want to have a bloodline. I can't select that bloodline using Arcanist (Blood Arcanist), because for it to not suck, I have to take it with the eldritch heritage feats, since my total arcanist level is only a max of 6, and taking bloodline development or the bloodline makes me ineligible for Eldritch Heritage later? What am I missing?

Nocte ex Mortis |

It does exactly what it says. You have a feature that gives you a Bloodline. Congratulations!
Edit: In other words. you now count as a Sorcerer of your level -2, plus your Arcanist level to determine your Bloodline. Is it whack? Oh yeah. Is it exactly what it says? Yup.
It still doesn't give you higher level Abilities, due to the wording of Eldritch Heritage, but, you can develop those for the low, low price of two more Feats.

friarzen |
It does exactly what it says. You have a feature that gives you a Bloodline. Congratulations!
Edit: In other words. you now count as a Sorcerer of your level -2, plus your Arcanist level to determine your Bloodline. Is it whack? Oh yeah. Is it exactly what it says? Yup.
It still doesn't give you higher level Abilities, due to the wording of Eldritch Heritage, but, you can develop those for the low, low price of two more Feats.
Actually, as far as I can see, RAW, Eldritch Heritage doesn't grant you the Bloodline at all. It only gives you the 1st level Power of the bloodline.
Which duplicates Bloodline Developments's effect for those characters that don't have Sorcerer levels. I would house-rule it so that BloodlineDev means you would qualify for Improved EH and Greater EH as if you had already taken EH, but that's just me.