So, if I use the half blood extraction and become a full orc do I lose archtypes/favored class stuff. Does it block the ability to continue in archtypes etc?
If the Archetype/Favored Class requires you to have blood of a certain type and you remove it, it should most likely say that you cannot progress in that archetype/favored class or not within the description.
It all depends on the Archetype/Favored Class you are looking for, or are playing.
From an arbitrary perspective, I would most likely say that you wouldn't be able to progress/choose specific archetypes that require you to have the type of blood you just removed, because that is a specifically set requirement that cannot be bypassed unless it says so.
Well for instance if I take the redeemer paladin half orc archetype, do I lose all of those abilities?
As far as I can tell, it only requires you to be a Half-Orc upon selecting the Archetype. Since it does not say anything about the character maintaining the Half-Orc status, the character would still be able to utilize the class abilities after the blood extraction.
Weird thought: Human with the Racial Heritage(Half Orc) has the Half Blood Extraction cast upon him.
What happens?
A very unhealthy orc. As there wouldn't be as much orc in there as the spell was expecting......
Wait that just gives too awesome a mental image to be the right answer.