Adding the Glyph system does not seem tenable, and also runs counter to the cash shop items that currently exist. I won't even bother arguing for it. While I would love to be able to implement cosmetic changes (and perhaps you could also argue for the gameplay-affecting glyphs as a method of testing prospective changes), I value my time more than writing up that proposal. This had a fun little research metagame to learning new glyphs, too.
Inscription crucially worked off of Herbalism items (Milling herbs) to make Pigments, which you then turned into Inks. There's a ton of room here to elevate the need and importance of existing game items and professions. Recipes to use Enchanting materials seem obvious, too. As of today, Alchemy costs are somewhat brutal all around, so I don't know if increasing the demand for herbs would be a positive.
Inscription also added a number of other interesting and useful items that helped each of leveling, PVP, and endgame:
- Darkmoon Faire cards, including four new lower level decks that could be turned in for great level-appropriate gear (and also got players more involved in the Darkmoon Faire)
- Enchantment vellums, which held varying levels of armor or weapon enchantments, that could be supplied to enchanters and in turn, once enchanted, be sold directly to players or placed on the auction house.
- Off-hand items to fill in itemization gaps on the road to 60, and some had fun little effects like breathing fire on an enemy or producing a small personal heal.
- Scrolls of Recall, which were consumable hearthstones (and perhaps could be alternatively used to attune to guild bases or summoning stones)
- Certificates of Ownership, which let hunters rename their pets (could add warlocks to this, or add a similar, demon-themed item)
- Stat scrolls! Scroll of Agility/Strength/Intellect/Spirit, all the way up to the highest tier. These are super handy when leveling, soloing, and even when doing dungeons. They're not going to get much use if any in raids, but having a way to actually make these is nice - though IIRC, they did have a couple that were raidwide utilities, which would be wonderful for when you are missing a specific class. You could invent new ones, too!
- Shoulder Inscriptions were the Inscriptionist's personal reward for training in their profession. They could only be applied to your own shoulder item and used up the enchantment slot. I remember these being high-tier, but I don't remember if they were BiS; it provokes thought when considering AD and ZG rep grinds for shoulder enchants.
Later versions of the game expanded Inscription to include:
- Crafting weapons; staves, specifically, which don't have any method of creation in the game until that point; this alone seems pretty useful
- Origami pets, fun little things
- Forged documents, leading to a quest to rip someone off for a bunch of gold (though this could be adapted for a variety of uses)
- Similar items to the forged documents that led to quests, such as paintings or gravestone inscriptions
- Some other weird stuff that doesn't appear to be remotely applicable to vanilla
Of the most interest to me, personally, is something that appears to have been removed in the beta for Wrath:
This is a truly appealing concept, especially given how vanilla endgame revolves around finding quests and ultimate class abilities through tomes randomly found throughout the world. An item that would presumably be used with this can be seen in the center of the below image:Decipher is an ability that was never implemented. It was presumably tied to inscriptionists' ability to open encrypted items and may have worked similarly to how lockpicking works on locked items.
The applications of Decipher seem endless and obvious to me; interacting with objects deep inside raids or hard-to-reach places in the world, and scholarly places such as the Scarlet Monastery Library, Scholomance, perhaps even the libraries of enemy capital cities or settlements could provide the spark for a lot of adventures.
In summary, even when completely disregarding Glyphs, Inscription has a lot of concepts to offer that both would fit into Turtle's vanilla plus concept, and enhance our experiences. There's a wide variety of items that would breathe more life into the game while increasing player interdependence on each other, and deepening the feeling of Azeroth as a more fully realized world. I acknowledge, of course, that this is dozens, if not a couple hundred database entries and changes, implementing items and skills, and would be a serious undertaking. Itemization would be a big deal, too, as would scripting quest turn-ins for new DMF decks and other prospective quests.
