Lanefan
Victoria Rules
@Manbearcat - though I might not 100% agree with your Agency Types breakdown, it's not bad; and props for putting the thought and effort into it. 
Is that vaguely right?

My take on it is Character Agency refers to the simple notion of, within genre (setting) and established fiction (situation), the ability to declare actions and-or roleplay your character in the moment without fear of veto or arbitrary denial. Of the various types this is the one most here-and-now at the table during play and requires the presence of both Situation and Setting (regardless who controls these); Situation is a bit more macro, covering as it does the framing around the character; and Setting even more so as it represents the backdrop onto which that framing is put.After looking over it for a minute, I think the defined Agency Types are solid.
In terms of the Vectors, I'm actually having a hard time seeing how Character Agency isn't actually subsumed into either Situation or Setting.
Thinking about D&D 3.5 / PF1, for example, a character's build would fall under the other two vectors.
If we're talking about core stats (bonuses, BAB), that's only relevant to Situation ("Because my fighter has an 18 STR, a +6 BAB, and is wielding a longsword, he is able to make an attack move that can cause harm to the ogre") and Setting ("He's obviously a large, powerful individual who will be viewed by inhabitants of the fiction thusly").
If we're talking about background / personality / traits / bonds / flaws / appearance, that's all Setting.
What is it in particular you're thinking about in therms of Character as a vector?
Is that vaguely right?