First, I think he picks Dave. I think his discomfort is due to the pressure Scott's put on him. Keith knows he was going to pick Dave but he brought the lynch mob to Dave's room. Now, with the proof of Dave playing the game, he still picks Dave. It was a dumb move, and that's why he's uncomfortable.
Second, Keith put Dave in this spot. Keith played the game by saying let's be honest, Dave would have kept me over you. Why did he need to say it? To alienate Dave from Scott, and then he lobbies Scott about how hard Dave is playing. I truly believe that Keith spun this web, and masterfully played it that Dave was doing it all. Dave is the geek that had to play, longer than Keith, to be here this long. And now his 1 alliance partner is playing him. What was Dave to do?

**Your analysis is kind of right, but you're missing that the point that it was Dave that started the first blow. First Dave asked the question to Tara to put her on the spot, and then he started cozying up to Scott to evict Keith just in case he had the power. That was actually fine with Keith, he understood he was playing the game. But he also told Dave that he was going to expose to Scott what the truth was unless Dave made it better. Dave refused to do so and Keith was *forced* to tip Dave's hand and expose his lies. Keith put Dave in his spot yes, but Dave put Keith into a position to do what he had to do as well--cover his @ss in case Scott or Holly had the power. It actually isn't personal to Keith--he's playing the game just as much to anyone else. It was Dave who didn't think Keith would call his bluff and expose the truth to Scott and Holly. Keith had to continue to play them in order to make sure he had the power to evict and not Dave.

Similarly, I don't think Charla is playing Dave. Rejection is a lot easier when you aren't forced to see the person you want 24 hours a day. Dave can't get away from Charla and it's making him nuts.