I like the relation to this system to bits of evidence and I agree that having some form of short hand would potentially be a lot more useful then having to add a large number of verbal ticks and caveats. ~i1.

I am concerned that a possible flaw in this shows that condensing all of the evidential certainty into a single number makes it easier to cause a typo in it, which would change the entire tone of your post. Example: ~i1: ~i11. While that is one character, it is the difference between "I'm just sort of spitballing this, based on a quick gut feeling." And "This is very self evident to me." However, you can have the same problem with emoticon typos, such as :) :(, so it isn't as though this is exclusive to the proposed system. ~i1r1

That being said, I find the general idea very helpful, because I could note someone replying to one of my posts, showing its flaws, and seeing "Oh, I didn't believe that all that firmly anyway, so I should update to the other side." In general, I think this would make me feel less defensive when given counter evidence, which would be a good thing. ~i2.