I could be wrong, but I'm looking at Kabukiden right now. In the shops, all I see is who can equip an item, and the raw stat number. It gives the name in kana, but it doesn't say what the item is (armor/accessory etc.) or whether it's better or worse than what you've got. Not telling you what it is isn't such a big deal because you can often tell by the name, but not telling you if it's better or worse means you've got to memorize everyone's stats.
Basically, like Xak said, you've just got to save before you go shopping, buy what you think you need, then double check everything.
Also, whether the characters come and go from your party depends completely on the game and has little to do with the menu design. FEOEZ keeps the same party through the whole game (except for one character who you play for, like, one dungeon). So does FFV.
One thing I do see I was wrong about, with Kabukiden at least, is that the item-exchange prompt does tell who who can equip what. So that saves some time, definitely. But it still doesn't save you from having to swap and check with the cumbersome split inventory.
FEOEZ has like a million different little disposable attack items, and it can be confusing to keep track of them, but the number of equip-able items is about the same as any other RPG.