At least "guess = low trust, ask/tell = high trust" is the pattern that I generally follow when dealing with people: strangers mostly get the "guess" treatment, friends may be "upgraded" to "ask" if it seems sufficiently certain that they won't mind it.

This pattern seems a little off, I wonder if you intended to convey the implicit caveat that you touched on in the preceding paragraph or if your actual pattern is a bit different to what your analysis would suggest. Strangers who for whatever reason you need to avoid offending (anticipate future interactions or believe they could harm you now) need the guessing. Strangers like, say, salespeople or various forms of gatekeepers like doctors are far better treated with Ask (especially if a Guess gambit isn't giving desired results). Or do you give dispensing-NPCs "guess" treatment too?