Hmmm--I'll have to read again with that in mind. I remember identifying what I thought were some themes the last time I read it. I think I picked out different stuff than you noticed, but that's probably because I was focusing on certain specific things, as I was reading for background for my horror novel series. I was trying to tie the part about Grendel being descended from Cain into the prehistory of my novel with the Watchers, etc. Later in my series I'm thinking of having a story with Beowulf's relatives in it--there are some references to Beowulf's ancestors in the poem which I've found allude to legends recorded in Norse literature that Tolkien also drew from, so I'm thinking of expanding on some of the characters mentioned and tying it into my backstory.