If rhizomatics is about subtracting the phallus (or not letting it in at all--deterritorializing it), then what about the "First theorem" of detteritorialization (174):

"One never deterritorializes alone; there are always at least two terms, hand-use object, mouth-breast, face-landscape.  And each of the two terms reterritorializes on the other."

1) where are the rhizome and deterritorialization, relative to one another?

2) what is an agent?  (Is this even askable here?)

1) The hand is a deterritorialization of the paw, the breast of the utter, etc.  As organs, these are not part of a body without organs (though as machines they are, I think), so if a de/reterritorialziation retains organ-ness, it is not a feature of the plain of consistency, but of order.  Further, there is no deterritorialization without reterritorialization.  This is not a becoming imperceptible, this is faciality.  The terminological confusion with deterritorialization is vexing.  It suggests the rhizome, because I think of trees and structure as territorial, but I don't think it is so simple.  One may have a tendency to read A Thousand Plateaus as two lists of synonyms: order and chaos, bad and good.  But both the dual and the morality of this reading give it away.

In the old dream of symmetry, the man (the subject) deterritorializes the woman (the object), in part by altering the specificity of her relation to the imaginary.  She goes from being a woman to being a woman, and the lack of terminological distinction is part of why syntax is so strange in these books.

2) I don't think I have an answer for this one.  Agency is not advocated by D+G.  Maybe statements like the one quoted above are their partial solution, or deferral.  Since people are not coherent entities, since there is perhaps no will, even, what passes for agency is the territorialization of the interaction of things (never mind for now what a thing is, and whether it presupposes ontology to even say "thing").  Humans interact with interactions by seeing in them, by making them (the interactions) a result of will.  Sometimes it is my will (for example, the pressing of these keys), sometimes yours (the decision to read), sometimes God's (the decision for anything I don't understand to happen).  But for D+G, these instances of will are de/reterritorializations.  Not made by me only as I witness, but from one object to another.  The water makes the plastic into a bottle by not flowing freely.

I'm quite skeptical of this, and maybe I'm wrong.  I'm also prone to solipsism.

EDIT: regarding deterritorialization: 

"It seems necessary to distinguish between three types of deterritorialization: the first type is relative, proper to the strata, and culminates in signifiance; the second is absolute, but still negative and stratic, and appears in subjectification (Ratio et Passio); finally, there is the possibility of a positive absolute deterritorialization on the plane of consistency or the body without organs." (Thousand Plateaus, 134)