I like this, overall I think it is a very interesting bloodline. With a few minor changes I could easily see me using this in my game.
I do have one criticism, I do not like the bloodline arcana. I feel that it is too expensive of a cost for the benefit gained. Tripling the casting time for these spells makes the ability only usable outside of combat situations, which defeats the purpose of having the cost to use the ability.
Outside of an encounter situation, the restriction is irrelevant because it doesn't matter how many rounds go by. In any situation where the restriction would be an issue (such as combat) it seems too restrictive, I would never want to use 3 full rounds to cast any Illusion or Divination. The benefit gained by these spells is just not worth spending 3 full rounds doing nothing except hoping an enemy does not get close enough to coup de grace.
Off the top of my head, I cannot think of anything to replace/modify the ability with, I will have to think on it. As I already said though, I otherwise like this bloodline quite a lot. Great work!