After reading more comments, I've updated my probabilities significantly. Here's what influences me:

1. Different commenters focus on different subsets of evidence. This makes me suspect that my own focal subset was incidental and probably depended on what order I encountered various claims.

2. Many items of evidence presented as fact (and which I relied on), such as cleaning supply shopping and the contents of the washing machine, are said by others to be rumors and were never presented at trial. This undermined a lot of what I based my judgment on.

3. The judgment of people who have followed the case very closely (e.g. jenmarle) is that Knox and Sollecito are innocent.

Together, these things make me throw my hands up in the air. I don't think I can clear things up without spending much more time on it, definitely not without seeking out new sources, and I don't know where to look. I now believe: Knox: 50%, Sollecito: 50%, Guede: 99%.