You could really tell that Clarke didn't care so much about his characters. It was somewhat refreshing, actually, to not have the book bogged-down too much with character development when there's this whole world to explore. Too bad about Rama II, I was wondering if I should read it or not. I'd also like to see some discussion on Blindsight eventually, we may have to do that one soon, since at least a few have already read it. I'm not so sure I got the same sense from Blindsight's intersocietal politics as you did, but there are some turns in there that I'm not so sure where they came from. But Blindsight's narrative has an important quality that you don't really get in Rama. In Rama, it's either a mystery or it has a plausible explanation that is almost certainly the right one. In Blindisght though, particularly with regards to motivations, the characters are guessing as best they can, but they get it wrong multiple times, and in the end you're not sure if they were right at all about anything. Then it turns out your narrator is prone to projection and has been mischracterizing the other characters. Too many authors encounter the problem of making this world full of mystery, but then they have their characters muse about these mysteries and just happen to solve them all while the author gently prods you saying "See, see? He's got it!" It's one of the great folly of all fiction, really. Watts fucks with that notion. You get the whole story through a filter, and he reminds you about it over and over. Were the aliens ever really even hostile or just self-defending? I'm not sure.
You're talking about the "unreliable narrator" which works when you've got a known, understood situation. "Who is Keyser Soze?" "What happened on the forest path?" It doesn't work in Blindsight. It doesn't work at all. You use unreliable narrators to give differing perspectives on a knowable thing. Even that last stupid little twist in Contact - "did she imagine the whole thing?" exists only to serve the purpose that the faithful deal with the doubts of others when they are certain of themselves. In Blindsight, Watts uses it to mask the fact that he hasn't figured out what the fuck he's doing, that he hasn't thought out the motivations of any of the characters, that he's constructed a society destined to implode and that the driving force behind his plot developments depends on logically inconsistent behavior from an entity that, according to his own story rules, can't exist. "I dunno... maybe it happened this way! Maybe it happened that way! You're the audience, you figure it out." No, asshole, write a decent story that doesn't have Great Pacific Gyre-sized plotholes so you don't have to hide behind "maybe I'm lying to you right now. You'll never know! 'cuz I'm so EDGY!" Sorry. Fucking HATED that book.