Perceval Day 3 (460-499)

4) We know of Chretien that he follows what he likes and what he believes the audience likes, therefore I believe that he realized that in order to make this story into a plausible and enjoyable story he needed to add the story of Gawain. Gawain is a recognizable name in that we see it repeated in many of Chretien's tales, it can almost be said that he is a more famous person and gives the people reading this a familiar face. But more than that I believe it adds credibility to Perceval and the grail quest because Gawain manages (we suspect we don't know as the story ends so abruptly) to introduce Kig Arthur and his court into the mix and really get them involved.
5) The thing that makes the least sense to me is that Chretien leaves off mid-sentence. It seems to me that any writer creating a work of art such as this would take the care to at least finish the sentence before stopping. It's for this reason that I believe that there is more of a reason behind his actions than just the fact he died, he did after all manage to complete his thought within the sentence. There may have been no ending but I believe that we can determine the ending based on the rest of Chretien's works. I think Chretien knew he was dying and left off here for that reason, he knew that he would not be able to give us the whole story so he instead gave us just enough to be able to give the story our own ending and little enough so that the ending is still determined for us.