My attempt to show the relevance of textual criticism for study of the historical Jesus is now published in the Journal for the Study of the Historical Jesus:
Bird, Michael F.
Textual Criticism and the Historical Jesus
JSHJ 6.2 (2008) pp. 133-156
This study argues that historical Jesus research needs to pay greater attention to the field of textual criticism and study of early Christian manuscripts. It is accordingly argued that the field of textual criticism impacts historical Jesus studies in at least three ways: (1) the textual integrity of the New Testament and the possibility of historical Jesus research; (2) the significance of the agrapha; and (3) text-critical contributions to historical issues in life of Jesus research.
I note that relatively few text critics have anything to say about the historical Jesus (Westcott and Ehrman are the clear exceptions) and few historical Jesus scholars take into account the implications of textual criticisms for their respective studies. The article also includes a study of Mk. 5.1 and par. as a text case of how the two disciplines need to be brought together.