There is one question that I am not good at answering :

How does one pursue FIRE while in a relationship with someone else?

The first problem is that finance experts are generally not relationship experts, you should treat all relationship advice from financial experts with a pinch of salt. ( Of course, I freely dispense relationship advice because I want to keep readers entertained. )

The second problem is that financial experts who solve these problems within their own marriage can only describe their solution based on one data point. This kind of wisdom is not empirical at all.

There are two obstacles towards crafting a satisfying answer :

The first obstacle is that, generally speaking, academic studies suggest that spendthrifts ends up marrying tightwads. This is unusual because we tend to marry folks who have the same political views and personal values. It's just that when it comes to money, opposites attract.

The second