one more reminder that I'm posting as a user not as a TL
1- We have our typing, we have a general idea of our role, and we have a preliminary list of build-around, defining sound moves from the original Defining Moves stage of the project. What other types of moves facilitate what we are trying to do here? What helps us achieve our goals of being a strong user of Throat Spray outside of what we already know? Are there sound moves that fill these relevant roles?
I think coverage is the best possible thing to give CAP 34. There are two coverage types that stand out: Fire and Water. Fire coverage hits Steel-types like Equilibra and Gholdengo, common foes that CAP 34's STABs are ineffectual against. Water coverage hits Ground-types like Gliscor that may be just bulky enough to revenge kill CAP 34. Coverage for Arghonaut feels largely useless, as its not gonna KO and CAP 34 will just get circle thrown, so I don't think that that should be a focus. The better way to beat Arghonaut is with stats, not with moves. I think the sound moves that we should look to build around are Clangorous Soul and Clanging Scales. No other sound move feels great now to build around and I don't even think any of them are that good on CAP 34 at this point. Sparkling Aria is
fine-ish but by no means a first choice when it comes to coverage. Boomburst is strangely not that good on CAP 34 because it attracts in Steel-types. I'd rather have coverage for them than Boomburst, so that too probably shouldn't be discussed in future stages.
2- How much support do we need from our other moves to find success in our role? What holes in our build do we need to patch, and what can be done specifically here as compared to Stats?
I think to succeed in the sweeper role from this point, CAP 34 is just gonna need some good stats and Fire coverage. That's really all there is to it, you could throw in some other coverage type or some utility in Taunt or Encore to ease set-up, but I don't think it is that complicated (the path, not the actual subs).
3- In contrast to the first question, what actively hurts us? What types of moves detract from Throat Spray, and what don't help us in what roles we're looking to fulfil?
Missed an L there SHSP, and you aren't one to miss many Ls...
To be honest, I think if CAP 34 needs to rely on another sound move besides either of the clanging ones, it's not gonna be viable. This is mainly due to CAP 34 just not wanting to activate its boost prematurely. It's good to have decent coverage that you don't need to commit to like that: think of it like Latios running both Draco Meteor and Dragon Pulse. It could be strong to click Draco, but it is also a large commitment that you can be punished for.
4- We have also just selected the priority-blocking abilities as our primary ability option. Does anything stand out as a particularly good fit alongside our ability? How important is the synergy between our moveset and this particular ability?
All of a sudden, CAP 34 is looking like a great check to a ton of Pokemon, which is awesome to see for its future competitive health. I don't think there is much room to synergize between moves and ability. Certainly, the ability makes it a whole heck of a lot easier to just run 4 attacks or 3 attacks + Clangorous Soul because Sucker Punch just doesn't matter. I will say, if CAP 34 can't actually take advantage of priority Pokemon (i.e. OHKO Kingambit when it counts) then the ability is pointless, so I think the best way to synergize with CAP 34's ability is through stats (more importantly, having some big ones).
I told myself I would stay out of other people's posts, but this point particularly irked me.
To me, giving CAP34 Clangorous Soul would be a sign that the CAP community simply doesn't trust itself to build a Pokemon that - through the cohesion of more subtle elements - makes Throat Spray the optimal choice of item
This is a ridiculous thing to say, flatly. The design space for this concept was always going to be narrow due to the nature of the concept: there's only so much you can do with items that don't see that much play (and don't for good reasons, the others are very good). The express goal of the community currently is to make a Pokemon that primarily uses Throat Spray. Nowhere does it say that the end result needs to be experimental and daring and risky. It doesn't need to be solved through subtle means, it just needs to be solved. This would be like not giving Chromera Boomburst because it's too obvious a way around Color Change or denying Jumbao Shore Up because that's the only move that synergizes with sand. Now, I don't disagree that non-Clangorous Soul routes are viable paths to take; I'm actually kinda divided on which route is best. However, discrediting Clangorous Soul because it is "unsatisfying" is wrong. Sometimes, the boring path is the right path (not that Clangorous Soul is boring, a notion I really don't understand for a wild omni-boost set-up move that takes your health and is only on one mon that doesn't even use the move that well... come on, man). Just because you don't think something is exciting doesn't mean it's wrong; try to stay objective.