It's an interesting thesis, but I'd advise copy-editing it for typos and such (there are a half dozen or so that I noticed), and I think a little more attention to the precision of how the arguments are crafted would be good also. For instance, it's not as clear as it should be why it matters what Belsey herself thinks; can't we just evaluate her arguments? (You argue no: key pieces of evidence you use require that her positivity towards poststructuralism be evidence against mundane interpretations. But it would help if you said so in some sort of point-blank way: "In cases where interpretation is ambiguous, understanding the perspective of the writer helps us resolve the ambiguity by using their perspective as context within which we can understand their arguments." Rather deconstructionistic, I suppose!)