I'd say Hypercharge/Heated Shot/Ricochet is very easy to perform because it's a specific structure that works exactly one way. It's fast-paced, and latency used to create some issues, but actually performing it is easy. I would say it's satisfying though. You have a rapid GCD timer and you're alternating between two OGCDs, and it's nice that Heated Shot and Ricochet are also maintained outside of Hypercharge and are not just buttons that exist for Hypercharge.
On BRD, it's the fact that the use of the OGCDs is not structured. There are procs for several things both on and off the GCD, and the cooldowns are short. I don't think BRD is that great at the moment, like I feel like having 2 selfish buffs and 2 party buffs all with the same 2 minute cooldown just feels kind of cluttered when it could be cleaned up, and Army's Paeon is kind of a dull phase where the job slows down considerably, but I'm also not a BRD main so I wouldn't take my opinions on it too seriously.
I'm not sure if this is necessarily the angle you were going for when you initially brought up the question, but I don't really think having a healer that has a 2-3 button GCD rotation with a small handful of OGCDs would feel great to the casual healer. Being able to keep the GCD rolling while weaving OGCDs is a skill that I don't think many newer, casual, or less experienced players are all that good at performing, at least not from let's play videos I've seen of players experiencing the story for the first time. It could also be in part the focus on being entertaining and engaging with their audience at the same time, though.
This is also why when I talk about wanting depth from WHM, I mention that it should stay low APM. A job can be fun without many OGCDs and can offer room for skill development, such as BLM, and it can also be simple while allowing for more actions to work with consistently throughout an encounter. And if this were accomplished, WHM could still feel easy to approach, just with more room for development from the more experience WHM players.
I'm all in favor of making the cards GCDs. Not everyone is on my side with that one, but besides the theorycrafting I've been posting today on here, my current iteration looks like this:
You have Solar Draw and Lunar Draw, two GCD actions with cooldowns. Solar is offensive cards, Lunar is defensive. They don't share a cooldown. Both drawing and playing cards are separate GCDs. The cards do not activate on your target immediately when you play them. Any party member can have a Solar card and a Lunar card, but not more than 1 of either. Celestial Opposition is another GCD that activates all Lunar cards on all nearby party members, activating their effects all at once, such as Bole's 10% mitigation. Celestial Fate is a GCD that activates all Solar cards. Celestial Intersection is a light GCD heal that activates both on a single target (good for tankbusters essentially). All of these GCD actions grant the AST a lodestar which orbits around them (both the drawing and playing of the cards). Stargazer is an OGCD action you weave that grants 2 stacks that allow your next spell or weapon skill to detonate one of the Lodestars, which deals malefic potency damage to the first target struck by the spell or weaponskill and 50% less for remaining enemies. Using Stargazer on another party member will cause them to detonate your stars for you, allowing you to spend considerably less time attacking enemies and having your party apply your DPS for you, though it can still be used on yourself for soloing.
There's more support for this system, such as Divination giving a solar card to the party as your buff window button, but that's the crux of the job concept. In addition, I also removed Combust in this concept for Asterism, a 2 charge GCD spell with a 30 second cooldown that generates 2 Lodestars on use. This means AST has no DoT, but has an equivalent that doesn't require a target and further supports their "attack through my allies" nature.
Currently, the limiting factor is the higher MP cost and the short 5 second duration. You wouldn't want to keep it up indefinitely because even in savage fights, you'll still have large breaks where no damage is being dealt, and trying to would just kill your MP. That said, it's entirely possible it needs more restriction than that and more structure. Perhaps that Premonition skill I mentioned, the 2 minute AoE burst attack could also apply 3 stacks of an effect that, when casting Gravity on that target, that's what gets you the 5% mitigation and consumes the stack, so you have 3 instances of light mitigation per 2 minutes. Or something like that could work.
Because Damage is king in this game, utility cards wouldn't be played on Tanks or Healers, so those effects would get ignored outside of the absolute most tragic scenarios. Because sure, Bole being a 6% DPS buff with an added 10% mitigation seems equal to every other effect, but putting that on the tank (unless it's DRK during their burst window) is just not nearly as valuable as ignoring the mitigation and putting it on the DPS anyway. You'd end up in almost the same predicament that the old cards were in.