What types are valuable to resist given CAP 32's supposed lack of bulk?
This isn't as simple as which typings are potent offensively IMO, but rather what typings are commonly run as attacks that suffer either from lower power in the metagame, or have fairly easy ways to be minimized in damage output.
Take Fire for instance. This is a very strong offensive type right now for various reasons: Iron Moth's ridiculous wallbreaking power, Skeledirge's snowball potential, Cinderace's frankly stupid Pyro Ball, the rarer but still potent options like Pyroak, Ceruledge, Armarouge. All of this then getting boosted by Jumbao's Drought, a regular sight in CAP matches, makes for a very spammable attacking type with crazy high damage numbers. Right now, Fire can often plow through our even sturdy resists under ideal conditions, or just with a Choice item. Our probably-mediocre defensive stats don't look ideal for taking on the heat.
It might be much more valuable (and easier) to hone in on types that aren't as insanely strong, but still prominent in the tier. Likewise, I find types that face multiple resists appealing, as it means we could lean into a double resist to nerf the power of said type to the point that our low bulk doesn't matter: even a lowly Ninjask can take two Close Combats from 252 Jolly Great Tusk.
With that in mind, here are some suggestions for what we could lean into resisting.
Fighting: Very common from powerful STAB attackers such as Iron Valiant, Great Tusk, and Revenankh, Body Pressers in Garganacl, Venomicon, and Corviknight, or just mons like Arghonaut running it because it's convenient. Close Combat is rather strong, but these mons don't always run max Attack, and Revenankh's Drain Punch is mostly dangerous because of its +3 Priority and healing versus raw damage. Plenty of avenues to resist Fighting as well.
Grass: With the most types resisting Grass, this shouldn't be too hard to see. Grass isn't even that uncommon in the metagame, given Jumbao being arguably S-Rank, Caribolt's steady rise to stardom, the occasional Meowscarada and Breloom, or just as coverage from mons like Iron Moth or Stratagem. More niche for sure, but still valuable and well within reach.
Ground: This does unfortunately only have two true resists, but Ground is nonetheless important. EQ and Earth Power are a regular sight in CAP. Even among Grounds proper, many aren't obliged to invest heavily into their Attacking stats, like Ting-Lu, Equilibra, some Great Tusk and Garchomp.
Fairy: Somewhat limited, but Fairy lacks any offensive moves over 100 BP, and that combined with only Tera as a way of boosting damage (compared to weather or terrain) makes Fairy feel rather stomachable. It's not too rare to see as coverage either.
Water: Water definitely ranges in terms of damage (Rain teams running CB Floatzel and LO Kril, or just the Wake), but I find enough weaker Water-type moves to be around that this is feasible. Toxapex certainly isn't threatening us Water STAB, but even more potent mons like Rotom-Wash, Snaelstrom, or Dondozo could be switched into rather comfortably. Water is also legit as a coverage option, whether that's Specs Dragapult or Plasmanta.
Steel: Rather uncommon, but that's fine. Steel tends to be on the lower end of power in the metagame, both as a result of the mons using it, and the very uninspired Base 80 BP of Iron Head and Flash Cannon. Steel is also rather predictable given it's barely worth using as coverage. The only major hurdles would be offensive Gholdengo and a boosted Kingambit: beyond that, I find the likes of Scizor, Iron Treads, Equilibra, and especially Orthworm's Heavy Slam very manageable.
Bug could be a contender, though it being largely relegated to U-Turn makes this questionable. It's not useless and could surely be built around to a degree, but the primary Bug-type move preying on switches isn't ideal. This feels more like a bonus than anything.
Normal is interesting now that we have Hisuian Zoroark around, and there's some pretty dangerous Normal-type moves that are quite good to be resistant to, like Dragonite's dangerous Extreme Speed, Boomburst from Chromera, any Facade users like Snaelstrom or Colossoil. Even resisting Rapid Spin can have benefits. I'm not as sold on it given the rather limited options, but it certainly has merit.
The importance of type immunities has been brought up in this thread a number of times. Of the many immunities CAP 32 could have, which are the most valuable in the current metagame?
There is some concern I have regarding immunities, and that's how the mons which throw these types out often have ways of hitting their immunities SE (Kril's Water STAB and Ice Beam vs Ground, Argh's and Tusk's Knock Off vs Ghost, Rev's whole STAB combo, the list goes on). I definitely think we'd need to consider how the opponent won't let our immunities go unpunished: the best way to make an immunity which is covered for is to either force the opponent into an awkward position, or outright deny them an option. Similarly, I think the best immunities are going to be those that the opponent doesn't have a good way around, or makes them use a less desirable move in order to cover for us.
Fire would be a fantastic immunity to have, allowing us to blank stuff as ludicrous as Tera Fire Choice Specs Iron Moth's Overheat in Sun, a move we'd probably fold to even with a resist. This would also thwart Torch Song, give us protection from Wisp, and help further secure Smokomodo as the weakest CAP starter.
Electric feels good if only for Kril, but there's plenty more Electrics worth keeping an eye on. The capacity to deny Caribolt Rapid Spin is quite valuable, for example.
Ground is always a good immunity, especially if it doubles as a grounded hazards immunity (thanks Earth Eater for complicating that).
Fighting (and by extension Normal) has lots of uses, whether that's blocking Triage Drain Punch or hard stopping an ID Press mon.
Ghost is strong, common, and somewhat hard to switch into with limited Darks or Normals, and how every Ghost has a way to harass them anyhow. A proper Ghost immunity that can reasonably handle the Ghost clickers in the tier would be a great starting point for CAP 32.
What types are useful offensively into the tier's current defensive profile? Are there any types that excel / struggle due to the current metagame?
Echoing
Psychic, this type is quite potent offensively right now given the lack of Steel, Dark, and opposing Psychic mons in the metagame. Being a type that smacks the various Fighting and Poisons roaming the tier is great already, but there's equal appeal in how few resists Psychic has right now. Neutral damage onto Garg, Dirge, Bao, Rotom, Kril in a single slot? Yes please, thanks. Factor in mons that often trade their Psychic resist when Terastalizing, such as Tera Ghost Gholdengo or Tera Flying BProof Equilibra, and Psychic genuinely sounds ripe for a killer offensive mon.
I also see some potential in Ice (little competition + some neat moves), Dark (rather unresisted in the metagame + some neat moves), and Ghost (it's ghost STAB). Normal gets a shoutout for having a lot of depth IMO given the wide array of moves and various interactions we can look into later on.
How much should we value CAP 32's ability to perform in the face of Knock Off, U-turn/Volt Switch, and entry hazards? Would weaknesses to these moves prove too detrimental to CAP 32?
There's a lot of factors that can make us vulnerable to Knock Off. Krilowatt is a prime example of a mon that falls off hard if it loses its item, even though Magic Guard would otherwise make for a great Knock absorber, just because it relies so much on Life Orb to be threatening. Being able to retain a niche even if we lose our item sounds like a good contingency plan, so I think we should avoid being too weak to Knock Off if it can be avoided.
A significant entry hazard weakness is either going to consume our item slot or restrict our Ability choice, which isn't amazing. There are mons that tough it out, however, if the power is high enough, though our implied low stats don't give a ton of confidence that we'd have the same awe-inspiring strength as Specs Iron Moth, Venom-E, or the late HDB-less Chien-Pao. I feel like we either avoid being too weak to hazards or simply ensure that our offensive capabilities and impact within a game are sufficient enough to outweigh the heavy damage we'll risk taking or demand support against (ala ORAS Talonflame).
Pivot moves are more interesting as having lower stats could leave us slower and weaker than whatever comes in, but that's not an easy assumption to make right now. If we can avoid taking too much damage from these that'd be great, but I feel the danger they present is going to be easier to gauge the more we know later on.