It sounds like you love the Church. Consider loving God with your mind, heart, and soul, and reading the First Commandment and then the Most Important Commandment in the Gospel. Perhaps a Bible which was not consecrated to the love of the Church (even if just by the intention of the publisher) should be used? Maybe that's just superstition.
While you sound confident, forgive me for suspecting you may find the notion that the Church could let anyone down to be a little unsettling. If you want to try a little Buddhism, and yes, you are allowed since there are practicing priests who have become Buddhist Lamas and not been excommunicated, consider getting in touch with the fear that the Church could be letting you down without divine rescue, and breathing the fear into your heart as black smoke. Then breathe out the Love of God into its place, even if you use exactly the conception you form of it by reading the Christian Bible.
The only Bibles to which I pay any attention for spiritual matters, are Bibles that have been approved by the Catholic Church. That said, some Protestant Bible translations are almost entirely unproblematical, such as the King James Version. I would be hard-pressed to think of a Bible translation that is capable of leading people away from the Catholic Church all by itself. They are all far more similar than different.
I don't find it unsettling at all to think that "the Church could let anyone down". Those who teach supposedly in the Church's name, yet allow people (for instance) to dissent from
Humanae vitae or speak in favor of women's ordination, same-sex "marriage", and so on, certain do "let people down". They are not always called up on the carpet for such teaching, and that is very wrong. Likewise, bad priests who have practiced sexual abuse
certainly "let people down", something with which I think even dissidents can agree. Millstones come to mind.
But to return to the idea of a priest being able (as in not impeded by Almighty God, the only way he could be rendered unable) deliberately to confect an invalid sacrament by withholding intention (or surreptitiously tampering with form or matter with the intent to render the sacrament invalid), if the recipient is beningly disposed in his own heart to receive that sacrament worthily, I cannot believe that Our Lord would withhold the graces that this recipient is seeking. The sacrament might be invalid, but God's grace is not limited to the sacraments. The blame would lie with the priest, not with the penitent. I don't know why it is so important to you, to create such a straw-man scenario, but if this satisfies some kind of intellectual or spiritual need that you have, that is up to your own judgment. To reiterate, this is not something about which Catholics worry or spend time thinking.
It's also worth noting, that if a priest thinks that a penitent is unworthily disposed to receive the sacrament, it is incumbent upon the priest to refuse to confer that sacrament, not to simulate it and withhold intent.
