Just a quick clarification here.
This has nothing to do with windows. Understand that, and many things can be done beyond the scope of a single file.
The "breath window" is not required. What is required is the Breath Element Gauge.
Same with the others.
You can certainly defined elements in one file and use them in another. As long as you don't have elements across files with the same ID name, it will work, I've done this.
Well, With gauges and stuff. Buttons are still flacky from what I can see.