no, i think you're right about the seam under the chin.  i think the placement is probably as little noticeable as it's going to get.  and i think you're probably close enough to the hairline.

i see what you mean about the moire being the display, not the thing itself, but i still think think the seam in the middle of the head is a PITA.  i've painted on skullcaps with no seam in the middle and ones with, and though i'm a rank beginner, i found the seam in the middle a real problem.  seams and hair or fur are generally problems. without knowing what you're doing and how you're applying the texture, i couldn't say if it's a problem that the stripes run sideways in the scalp, but if it the UV map goes up and down there but displays left to right, it's also going to be a PITA. or if to paint on it, you need to change direction from the top to the bottom of the head. 

again, not a big deal if her head's always covered.  i think it matters only if you personally like to use integrated hair as a base (which can be very useful, as skullcaps have drawbacks), or if you have a male planned and want to use the same mapping (cause more guy textures have stubble on the head).  but then, if you're going to use the same mapping on a male figure, body hair is a whole new issue.