There's an addon that will show you the soft caps. There's other stats not shown by the standard interface like your block, parry and dodge chance. Just displaying data available through the interface that isn't displayed by the standard interface is pretty easy. What that's actually going to mean when it comes to combat is a whole different story. They don't provide the formulas, just the numbers that, somehow, are used in it. Is it (x+y)/z or x+y^z or x/c+y*z? That part is like your basic science and physics classes. You control variables, collect data and try to determine the relationship. You can make some educated guesses due to the context and names. As the damage rating on the weapon goes up you likely hit for more. Is the crit multiplier a constant or a variable? If a variable what does it depend upon? If it depends upon something is that dependency linear, quadratic or exponential? That's theorycraft. That takes board players that want to see if their general impression of how things work is supported by the facts. That's a long, slow process.

PS: You can help in that process by getting a DPS meter and doing some experimentation. Yeah, the additional stats would help, but until you understand what you already can see the rest doesn't really matter.