Cthulhu, for example, strikes me as an entity that is worshipped as a god, but is also ripe with potential for being a patron too. I think that trying to define such beings in strict, neat little categories would be to miss the fact that they are a varied bunch in power, outlook, and capriciousness, and that in and of itself makes rigid separation of patrons and deities futile.
I see the whole concept of Cthulhu as this:
We still survive because
1) he was bound
2) we are beneath notice
I suppose if he is bound he could bargain power in an effort to forward the cause of him being released. Being released would mean that he would pretty much destroy the world. Maybe his priests long to be in a "better place" and hate the world.