Most of this confusion here could be eliminated if spells that you can eventually learn, but don't have the correct level for yet, were simply marked with a greyed out "Learn." (see example below)
Ideally, right-clicking on a spell scroll should show more useful information in the Item Details section, like the spell's base level, what classes can learn from the scroll, which classes can cast from the scroll, the spell's domain (ex: Evocation) and the descriptive text that you would normally see on the help page for that spell (or a link to that spell in the help screen). If this can't be done due to the way items are handled (where somehow the spell scroll description can't be changed to reflect individual items) then at the very least, the spell scroll name field should be appended to include the spell class(es) and base level so we don't have to guess.
One other UI overhaul that's badly needed in the bag/chest inventory line. First and foremost, if you have a weapon, armor, or spell scrolls in a chest or bag, there's no reason why you shouldn't be able to see which ones you can equip/learn while it's still inside the bag. Removing it from the bag doesn't suddenly make a mace more identifiable as a mace if your character doesn't have the feat to wield maces.
Additionally, I would suggest rejigging the inventory screen, and relocating the range weapon/range ammo slots, and Fire, Cold, Shock, Acid, Sonic resistances so that bag/chest row(s) can be displayed as a permanent 3rd row, and won't automatically close as soon as you drag an item out of them.
If you have multiple bags/chests, it should either toggle views when you click on another container item, or turn into a scroll window to allow as many rows as you have bags. This would be ideal, since it would allow you to transfer items directly between containers without having to drop to the floor or go: bag, inventory, inventory, other bag for every item you want to move.
Here's a photoshopped version of how I think the inventory screen should look:
