Me thinks, your paper written when you were 17 wasn't far off the mark afterall. I am persuaded by a leadership training I was part of a few years back who taught me a trust "equation" which combines credibility, reliability, intimacy, and self-orientation. This maps to your earlier ideas about actions (credibilty, reliability) and words (intimacy, self-orientation).

There's more here, if you are intrested (written during the 2016 primary elections): https://bporteus.medium.com/the-trust-quotient-and-how-the-balance-of-the-us-election-depends-on-it-c877e8ea903c