I think it's very hard to maintain a culturally relativistic position with regards to that book. It's kind of morally repulsive although it's hard to imagine it wasn't trying to be. I feel like it's meant to emblematize both the barbarity of tradition (the villagers, in particular Wad Reyyes - no coincidence that he was best friends with the narrator's grandfather, the somewhat saintly spirit of tradition in the village!) and the barbarity of Western culture (Mustafa Sa'eed's past). The narrator is semi-detached from both, he hasn't thrown himself wholly into either, and he winds up being one of the only morally neutral characters in the book (although even he is implicitly condemned for his passivity with Mustafa Sa'eed's wife)--and almost drowns himself at the end of the novel... I thought it was also an interesting microcosm of discussion of colonialism in general. More like a grim novel of ideas than a convincing story in and of itself. But it also had beautiful moments! It definitely made a strong impact on me, but like you say, hard to sort out.

(Sorry to babble so much in your books post, fahye! I just hadn't found anyone else who had read it and wanted a chance to discuss the book a little.)