But, I also know that no amount of legal paperwork is going to make a happy marriage.
This is called, in logic, "moving the goalposts", meaning you are changing the goal of the debated action. The purpose of a prenup is not to ensure happiness, because it can't. So your point is irrelevant.
A woman of very low character is going to get what she wants even if she has to take you out of the picture in the process, while a woman of high morals will never resort to having the courts impose vengeance for her.
In our day and age, ANYONE can go from pious to a loss of faith in a matter of a few years. I'm not saying it happens a lot, but there's plenty of people I know who grew up Trad who are now atheists. Women can lose their faith just like men can get addicted to vice or drinking.
Skip the paperwork and ask God to send you a virtuous spouse.
Marriage is one of the most important and difficult endeavors 2 people are EVER going to go through (especially in our day, when there is no help from the Church, when families are spread out, when society is anti-marriage) and your answer is that prayer will solve everything. That's true only to a certain point. We are both physical and spiritual beings, therefore whatever we do requires a physical action, in addition to prayer.
I can pray that God sends me food each day, but I have to work for it. I can pray that God helps me find a new house, but I have to go look at houses to actually see which one is good. I can pray for a happy marriage/pious spouse, but 1) a happy marriage takes CONSTANT effort and for a catholic to stay pious takes CONSTANT effort, both physical and spiritual. Not one or the other, but both.
Your argument is, like most of the arguments on this thread, pure idealism, and skips practical/physical action.
And work on making yourself a virtuous potential spouse too, which would seriously lessen the likelihood of your future virtuous spouse wanting to dump you.
Thank you for being honest and using the word "lessen" which does not mean eliminate. Therefore, you admit the threat of divorce still exists. Therefore, a prenup *could* be of use.