My comments don't seem to stay posted at Richard Beck's site - so I repeat one here. His note on Trinity and Psychology is fascinating - see shared link on the right.
It could be also that the theoretical formulation of Trinity is important for your questions. E.g. your note "That is, while we recognized the preexistence and divinity of Jesus and the Holy Spirit" has two red herrings in it. Pre-existence and divinity are both unmeasurable. More suitable frames - like "God was in Christ reconciling the world to himself" or "if you by the Spirit do put to death the deeds of the body, you will live" seem to me to be Trinitarian but they have to do with present behaviour in present time based on the past event of the work of the Son that the Father gave him to do. When you also extend the question to the ambiguous nature of the service of the Son - i.e. Christ as servant to the circumcision and "I called my s(S)on out of Egypt" then your questions could also discover what aspects of 'Trinitarian' belief could impact even those who do not know how to make 3 into 1.