While I'm sympathetic to the idea that "you are likely to begin believing things you say to yourself frequently, and furthermore you are likely to act in ways to make these beliefs come true," I'm not sure I'd use Scott Adams as the prototypical purveyor of this idea. He is known to have beliefs difficult to characterize as "rational," notably a belief in intelligent design creationism. The Wikipedia also cites him as being a hypnotist and a vegan; these are not inherently irrational, but I don't have further sources to analyze Adam's specific perspective on these issues.

As a person who's completely obsessed with the TV Tropes wiki (and has only just recently started to peruse this site), I applaud any efforts to apply that model to furthering the cause of rationality. One problem I foresee, however, is hinted at with your comment that "the trope explanation itself will be a short bite of joy" and that this promotes opening up new tabs to acquire said bite of joy. If you're trying to compare the postings themselves to the trope descriptions and the comment threads to the references, the analogy breaks down due to the length of the posts. It's simply not practical to whittle down the post lengths such that one could reasonably say "I'll open a couple more of these, I'm sure it won't add too much time to my browsing session." This sort of multiplicative effect might come into play on the LW wiki, but I fear it cannot drive traffic back here to the degree you would hope.