Sarish is Known to His Chosen

1) You still learn a spell. The +1 to Arcanum (Sorcery) is only if you are already trained in it, since otherwise it would be “gain Arcanum (Sorcery) as a trained skill. . . oh, you have it already? Ummm. . .”

2) No. Bloodline talents are talents, so unless it specifically says like bonus’ from the same source (in this case, static +1 from a talent) do not stack.

You may now use Arcanum (Sorcery) untrained with
a bonus equal to your Bloodrank. You have also instinctively
learned how to cast a single spell. You learn a single spell
from the Wards or Blood Traditions. If you possess Arcanum
(Sorcery) as a Primary skill, you instead gain a +1 bonus to
all Arcanum (Sorcery) Action Skill Rolls.

1) You gain a spell which MUST come from either the Wards of Blood Tradition. This spell is gained as if you used Learn Spell (ta).

1) If you are not trained in Arcanum (Sorcery), you are able to use the skill using your bloodrank instead to cast the spell that you have gained through your bloodline power.

2) If you ARE trained in Arcanum (Sorcery), then you must use Arcanum (Sorcery) to cast the spell gained through your bloodline power, and you gain a +1 bonus (not +1 rank) to all Arcanum Action Skill Rolls, similar to Prodigy (Sorcerer-Priest of Sarish) (ta).

For Learn Spell:

Choose a spell, which must be of a Tier equal to
yours or below, from a Tradition you already know.