Honestly, I think the whole topic of Probabilities and how the dice may or may not be practically balanced is sort of counter-intuitive to why the designers chose to design them the way they did. I may be the only one here... but I am sick to death of crunching numbers. I'm tired of maximizing the potential of character versus the dice. I'm tired of playing against the dice.
I just want a cool story with adventure. I don't want to look at spreadsheets. As a GM, I want to focus on the narrative and the relationship I'm building with my players. I don't care about the challenge, so long as it is represented in the dice. If it's at least represented, then I'm okay with that.
My point is, maybe the designers really did just go on feeling. And so what if they did? You roll the dice, most of the time you achieve your goal. Sometimes you don't. Sometimes things go really well in your favor. Sometimes, things go really bad against you.
I think contemplating the dice pool frequency of failures, threats, successes, etc. is simply not conducive with this game for the specific reason that... it really doesn't matter. It's a mentality carried over from D&D and other RPG's where people are trying to game the system, rather than playing the narrative and being the character. It's drama, folks. You're the hero. Most of the time, you advance in plot. Sometimes you get your hand chopped off and fall down garbage chute. Those are rare occurrances, but they do happen.
If you're focusing on the right things, these other issues simply don't matter. I think this is exactly why my player had a hard time with my decisions to upgrade to a Challenge. He was looking at the numbers and not the narrative possibilities.
In short, these negatives are not in the game to stop you from doing what you want to do. Sure, that is a possible side-effect. But really, they're just there to make your actions interesting.
Edited by Raice