Soldering leads does not meet the typical definition of "hotswap." This line is confusing and should probably be broken into two sentences to make it clearer what exactly you are saying is hotswapable.
It's an interesting project. I think on the PC this would be an easy software fix to change those analog input to be far more sensitive effectively making them hair triggers. If you could access the controllers firmware you could fix it there too.
I do like the idea of being able to swap about the feel of the actuation. For games that use the triggers as a button you'd have something like a blue or brown, for games that use the trigger as a 1D stick you could use a red. I could see a whole market for swappable triggers or even face buttons. But that would add some bulk to the controller. Maybe something for a Duke clone.