Useless things? Note I'm looking at this from the perspective of "What would a new player figure out on their own?" so things that are worthless based on having too much knowledge of the game doesn't count.
Hairband: Obsolete in the first town it appears to the Plumed Hat (forget it's name in this game, so going with SNES name, too lazy look it up), and use-able by Terra only initially contrast to Plumed Hat's universal nature. Celes has it equipped by default but unless you somehow got a Main Gauche from every single Merchant you fought (1/8 chance), you'll most definitely have a spare Plumed hat for Celes when she rejoins.
Rising Sun: So here we have this weapon that's a step up in power from the Hawkeye...gotten only in the Colosseum, which is VASTLY inferior to the store-bought Sniper (both much weaker and lacks Sniper's Hawkeye effect), and usable by Locke only. Insult to injury? The dungeon you get Locke gives him the Wing Edge, his strongest Boomerang in raw power (though useless on undead, but defer to my Sniper point.)
...and no, I don't care that it leads to getting a Red Jacket, it's just an extra step that's completely unnecessary seeing as the earliest access you have is starting with a Fuma Shuriken, and chain betting anyway.
Light Robe: Hey look! A store-bought Robe in Thamasa that boosts Magic! Sounds great for Relm and Strago! Oh wait, the Magus Robe is store-bought AT THE EXACT SAME TIME and is better in every single way, let alone in a town you're likely to visit first.
-As a side note, I question if this was suppose to be usable by Terra and Celes as well, while keeping them restricted from Magus Robe. That would explain a few things since it'd be a valid option for Terra/Celes mage builds for people who didn't know where the Minerva Bustier is, which most new players won't (it's essentially an upgrade from the Silk Robe...a very belated one granted.) No, this isn't me going "Terra/Celes got shafted" since that'd be stupid, they're the last characters who need better gear. This is more questioning the logic of the equip and pondering original intent, since it's very strange that an item appears later in a store but is straight up worse than something people are likely to see earlier...
Crystal Sword: SPEAKING OF WHICH, here's a weapon straight up worse than the Falchion, which is also found in Maranda, AND it's usable by less characters too (Locke can use Falcihon but not use Crystal Sword.) To make matters worse? Unlike Magus Robe, when you first see access to Falchion, you'll have Celes and Edgar in your team likely and thus likely equip it on them, such that when you come across Crystal Sword in Jidoor, it's just worse.
Masamune: If you did Cyan's Soul before Phoenix Cave, I GUESS it'd be useful as Cyan's strongest weapon...thing is, I'm under the impression most people do Phoenix cave first, thus fight Red Dragon, thus get the clearly superior Murakumo.
And if someone brings up a knowledge-able player, I'll just spin around and say Cyan shouldn't be using either weapon, as Murasame is better than both since Cyan's still relying on Fang, and Murasame at least boosts evade. Plus there's Kazekiri which gives Cyan a reason to care about his physical.
Regal Gown: By the time you get Relm, you'll probably have already beaten King Behemoth meaning you have 2 Behemoth Suits...meaning you Relm's best armor, and this is worthless (hence why it's often suggested it becomes a Minerva Bustier.)
Moogle Suit: ...see Regal Gown, basically, only add Strago into the mix. Also inferior to the Magus Robe, a storebought armor.
Mithril Helm: 1 Defense vs. 12.5% HP and 10% Evasion from Green Beret, it's a joke really. Also storebought at the same time, so limited quantity argument falls apart.
I'm sure there are others, but that's a good list of items that really serve no purpose, be it from a newbee or expert standpoint.
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