I feel like I'm missing something when it comes to this game. Maybe it's because I'm playing as a dedicated spellcaster, which makes combat relatively dull (press button and wait 30 seconds for a spell to cast, while your party does all sorts of exciting shit), but I can't imagine myself enjoying melee with such a crappy framerate either.
For what it's worth, I enjoy melee a lot despite the 30 FPS. Vocations like Assassin and Mystic Knight, many of whose skills rely on semi-precise timing, still handle well enough. I'd encourage you to try either Mystic Knight or Magic Archer...they have a lot more "play" to them, especially the Knight. If you don't mind having mismatched stats, you could go Assassin, though since you've leveled up in magic-based vocations, your physical strength and defenses might be a tad low. But optimized stats don't really matter for anything much besides having your pawn rented by others more often or challenging the "online" version of the secret boss.
While playing as a Sorcerer in Dragon's Dogma is probably the most satisfying representation of magic in an action-RPG, I think vocations with melee applications (beyond whipping enemies with Brontide) have a lot meatier gameplay, especially if you don't know the ins-and-outs of how pawns work or lack access to well-built ones. A lot of the fun of being a Sorcerer is rolling with an expertly-trained Sorcerer pawn (or two) and spell-syncing some high archmagicks while a competent Fighter/Warrior/Strider (pair) draw the enemies away.
In general, the game somewhat encourages vocation switching, so there isn't any penalty to feeling out what playstyle you like.
Dungeons are thus far rather boring, they're basically mostly linear corridors with monsters, with barely any environmental interactivity.
Yeah, dungeons are more or less places to go and fight monsters, with most everything in the dungeon built around the combat. The Witchwood bog is tailored to it's occupant(s), Soulflayer Canyon is mostly all about the perilous heights, and the Ancient Quarry is pretty much geared to help lower level players fight the Ogres within (narrow corridors for magical bolts with lightning enchantment or Ricochet Bolts from a spellbow, copious amounts of combinable resources for Poison/Oil Arrows, plenty of explosive barrels to use on the baddies, etc).
It's a combat-centric game, of that there is no doubt. It's not really Ultima Underworld. I don't think dungeons compare too poorly to something like, say, Risen.
but it concluded with a stupid, scripted Griffin battle.
I kind of liked the scripted sequence before the Griffin fight. Mostly because the game uses them extremely sparingly (there's only one other battle that has some scripted set-pieces preceding it...wanna guess who it is?) and how open the combat system generally is. I didn't mind a little bit of railroading for the sake of spectacle and buildup because I knew that in any given fight I'd have a bevy of ways to take down any monster, so being pigeonholed for a bit wasn't too disconcerting.
Plus, that entire sequence is "punishment" for failing to kill it outside of Gran Soren, so it isn't even mandatory.
Do all the status removers actually become useful at some point? It seems like the game would like to make preparation a major thing, but I've yet to see any content that would support it.
Nah. A lot of the status ailments are exceedingly rare and many of the curatives are there for completions sake or for supporting the combination mechanics. There's scant few enemies that inflict tarring, curse, lowered statistics, and freezing solid. The last one can be negated by stick-waggling that becomes ever more trivial the bigger/stronger your Arisen's body is. Basically, carry a little Nightcry/Mithridae, some Secret Softener/Cockatrice Liquor (petrification), a Nostalgia Dust (possession of a pawn), and Panaceas or Sobering Wine in addition to health/stamina restoratives. That's mostly all you need for the curative tab.
The rest of the inventory depends upon vocation. Non-magical classes might benefit from magick jewels, grimoires, and cameos to have spell-releasing consumables. Vocations that use mundane bows have a bevy of special arrows they will likely want many of. All vocations can benefit from Periapts to significantly boost statistics for a time. Amassing a good deal of materials/rarities from defeated foes or the land is helpful when enhancing things, although those goods will quickly be sent to item storage and therefore won't spend much time in your inventory.
And it may be beneficial to carry multiple types of one weapon/armor class if they have significantly different effects. Permanently enchanted weapons are the foremost example, but Level 3 Rusted/Anneled/Golden Weapons can be helpful for dishing out debilitating effects on hit in exchange for lower damage.
Basically, don't worry too much about going full pack-rat; this isn't Gothic, a D&D game, or whatnot. Items aren't that big a deal and mostly aren't worth wasting time fretting over.