As far as Weak Armor goes, it's worth noting that, assuming no Weak Armor, a lot of physical bulk is required to have a good chance against opposing priority users. A hypothetical 0/0 Skarmory without the Steel typing does not survive Choice Band Scizor's Bullet Punch after Stealth Rock and two turns of Life Orb recoil and sandstorm damage. Salamence, an actual example, experiences a similar situation if Scizor comes in to revenge kill (i.e. not Intimidated). Cloyster without a Shell Smash takes 40.24% - 47.71% so it might survive. So yeah, a LOT of physical bulk. I'm trying to decide what this means for the Weak Armor suggestion, but it is pretty interesting that CAP 4 would probably have issues with at least Choice Band Scizor and Choice Band Dragonite without a Defense drop.
Now, as for No Guard, maybe it's best to communicate it from a different angle. What I said before could be interpreted as a criticism of the luck factors in Pokémon in general, so I suppose that that could warrant a better explanation. See, we all know that luck is part of the game. A lot of things are part of the game, but the whole point of CAP is to alter the game to learn about some aspect of it. In this case, I claim that miss-based luck factors get in the way of the current concept. They're not irrelevant to choice-based risk; on the contrary, they are more relevant than they could be for perhaps any other concept we could come up with.
Think about it as an experiment. Consider Salamence switching into Therian Landorus (say it has to for some reason), which has a counter to the possible switch-in with Stone Edge. Stone Edge has a miss rate, so we now have two layers of risk in the same turn. Therian Landorus has to use Stone Edge to catch Salamence (and remember, there may be other factors affecting the decision), AND the move has to hit. Hence, even if our focus is on learning about the former form of risk, the latter form has a significant impact, altering the "result" of the "trial". In essence, with No Guard, we are controlling one variable to focus the results of the other. You can say whatever you want about whether luck and risk are the same or whatever, but it's not really relevant when we definitely can identify two (or more!) distinguishable forms of risk in situations like what I described.
My hope with this concept has been to look at the long-term impact of "risk" on an entire match. A decision that's generically considered a "risk" may or may not be taken depending on the overall match situation. A losing player might make unpredictable desperado moves. If a specific opposing Pokémon is a pain to your team, you might take "risks" to try to get rid of it. Every decision has a context behind it. Sometimes a match degenerates into a last turn guessing game. Okay. I'm not sure how that's supposed to be detrimental to the overall idea of risk throughout a match, though.