Yes, to all your questions.
It is our fiat. (cf. Paul VI, Marialis Cultus, 28) “Christian obedience is unconditional submission to the will of God. But your obedience is more strict because you have made it the object of a special giving, and the range of your choices is limited by your commitment. It is a full act of your freedom that is at the origin of your present position: your duty is to make that act ever more vital, both by your own initiative and by the cordial assent you give the directives of your superiors.” (Paul VI, Evangelica testificatio, 27)
You give all for obedience, but the principle is your cooperation with God: apart from the mortal you are obedient - “Faith is, first of all, a personal adherence of man to God. At the same time, and inseparably, it is a free assent to the whole truth that God has revealed. As personal adherence to God and assent to his truth, Christian faith differs from our faith in any human person. It is right and just to entrust oneself wholly to God and to believe absolutely what he says. It would be futile and false to place such faith in a creature.” (CCC 150)
The Church requires us to give an assent, i.e., to believe all of her despite not understanding all of her. As Saint Augustine says, “I believe, in order to understand; and I understand, the better to believe.” (CCC 158)
Assent is our part with the action of grace in the Holy Spirit:
“Justification establishes cooperation between God’s grace and man’s freedom. On man’s part it is expressed by the assent of faith to the Word of God, which invites him to conversion, and in the cooperation of charity with the prompting of the Holy Spirit who precedes and preserves his assent” (CCC 1993)
It is not only personal but requires a communion of life.
“Even the best structures function only when the community is animated by convictions capable of motivating people to assent freely to the social order. Freedom requires conviction; conviction does not exist on its own, but must always be gained anew by the community.” (Benedict XVI, Spe Salvi, 24)