There is no morality, per se, in paying taxes. If anyone thinks there moral obligations to their fellow man is satisfied by paying taxes they are mistaken in the teachings of Christ and the Church.
If charity does not come from an act of free will, it is not in accord with our obligations as suggested by Christ or the Church.
Faith IS NOT a rational yet unconfirmed belief? Who told you THAT? There is nothing rational about a faith in the Church or Christ. It is an act of free will, and BELIEF that cannot be explained rationally. Is it an act of reason to think something must have preceded the origins of the universe? Perhaps, but that does not lead to faith. You are missing a step here.