Your definitions only show the absolutes, though. It goes from "I know everything" to "I can't draw any conclusion".
My point being that these definitions don't make much sense, if almost anyone is somewhere inbetween, but not actually agrees with any specific corner.
Honesty is not relevant. You're also not claiming to know that the moon landing happened, just that you believe with a high degree of certainty that it happened.
Of course honesty is relevant. If you make a claim you cannot back up, then that is a dishonest claim.
Also yes, in everyday language people claim to know things. People do say "the moon landing happened", and not "i'm convinced the moon landing happened".