Your final points are the most important. I'd add a final, yet rarely done step. Nietzsche was one of the first to speculate that we are driven by unconscious drives that even manipulate our supposed rational, logical thought. His example was "the prejudices of philosophers", that in effect a thinker decides (unconsciously) what The Truth is and then constructs his argument (dialectic) in support of it. Although Nietzsche didn't expand the concept, I'm sure other have, and the principle is applicable to all human thought. In other words, one can neatly sidestep what seems like the critical but often unanswerable question "What is really true?" with the more utilitarian question "Why is it necessary or desirable to believe that X is true?" Even the layman can do this, to some extent, although ideally he'll have some familiarity with psychology. For example, one can gain much insight into the news or even a public figure by asking not "Is he telling the truth?" but questions like "What are his likely motives for wanting to believe that such and such is true, or that others must be convinced of them?"
Your final points are the most important. I'd add a final, yet rarely done step. Nietzsche was one of the first to speculate that we are driven by unconscious drives that even manipulate our supposed rational, logical thought. His example was "the prejudices of philosophers", that in effect a thinker decides (unconsciously) what The Truth is and then constructs his argument (dialectic) in support of it. Although Nietzsche didn't expand the concept, I'm sure other have, and the principle is applicable to all human thought. In other words, one can neatly sidestep what seems like the critical but often unanswerable question "What is really true?" with the more utilitarian question "Why is it necessary or desirable to believe that X is true?" Even the layman can do this, to some extent, although ideally he'll have some familiarity with psychology. For example, one can gain much insight into the news or even a public figure by asking not "Is he telling the truth?" but questions like "What are his likely motives for wanting to believe that such and such is true, or that others must be convinced of them?"