Here's my unfiltered list of point-by-point ideas, changes, bug fixes, and code implementations that Blizzard Entertainment should add to the Classic Era servers of World of Warcraft. Or I wish they did at least. So, in no particular order, here's some stuff I'd love to see added to the game.
1. Unlimited debuff slots, especially useful in raids, and even more important for Paladins, who can now cast that god damned damage-increasing Seal of the Crusader judgement before a fight.
2. Remove underwater mining nodes. How can you mine nodes underwater? Replace them with a few more on the nearby hills.
3. You don't get dishonorable kills while in a raid; only the person(s) attacking the respective NPC gets one.
4. Why do my buffs get rearranged when going through a portal? Maintain the order at all times.
5. Paladin auras affect all nearby friendlies or everyone in your raid, like in Wrath of the Lich King, not just your party.
6. Items such as the Red Whelp Gloves should have their color actually be red!
7. Fix the PVP glitch where, after you duel someone or whatever, the guards in various places might attack you. Especially important in Hardcore servers.
8. Z-axis change in Classic Era. Again, very important in hardcore, but it would be very nice to see it happen in all Era servers.
9. Implement a new interface option: toggleable achievements. Those who want the pure vanilla experience will simply ignore this. Those who want to perfect the game will go for it. It would make people play like crazy! Imagine the raid attendance for getting the full armor set achievements.
10. Update the game to display quest markers above NPCs' heads even for low-level quests. Completionists rejoice!
11. NPC enemies should have a toggleable 'kill count' above their heads. I like the idea of seeing a Hogger with a 57 kill count above its head.
12. Implement a solo dungeon competition/ranking system like in Diablo 3. Coupled with the achievement system, this would encourage people to play for years in pursuit of the perfect score or speed run.
13. Implement a lowest-level solo dungeon competition. Imagine how many would re-level from the start to try this out in various specs and class combinations.
14. Allow the awesome Chronoboon Displacer to stack with others, so basically you have multiple rebuffs available. Still keep the cooldown though. Works well with speedruns.
15. Leaving RP aside, we should have one giga-realm for PvP and one giga-realm for PvE so the world feels more alive than ever.
16. Update the spell tooltips. See, for example, Judgment of the Crusader for the damage increase via its talent, not showing correctly on the debuff info on the judged enemy. Also, Blessing of Might, Improved Retribution Aura, and Battle Shout are not displaying correctly on self or friendlies the correct attack power increase. There are plenty more issues like this that need fixing.
17. New classic journeys should begin on Era Realms, and then those characters transition to TBC servers as usual, then WotLK or whatever. Enabling Era-stuck players to interact with seasonal players will transform the world in terms of aliveness for both groups.
18. Fix those buggy murlocs in Redridge that have been stuck for decades in those places.
19. Implement a "log out and play an alt while waiting for a queue on a different character" where you are notified on the alt when the queue is done. On the load screen, just transport your main character to the battleground.
20. The layers system should be mob-specific AND player-specific. So you don't see different mobs.
21. Fix spell logic. You can't cast Blizzard while inside a house. You can't lay a trap inside a house; it needs terrain, etc. Implement the inability to cast some spells underwater, unless an Elixir of Water Breathing is used. How can you cast a fireball underwater? This doesn't make sense.
22. Fix that goddamn mining vein on the border of Westfal with Duskwood situated in the river and not being mineable.
23. Fix the quest where Kinley says she runs, just run! Fix the pathing of all escort quests.
24. Fix the pathing of pets/companions so they don't constantly sit superimposed on your avatar.
25. Spells such as Siphon Life should stop working (auto-debuff) if the caster dies.
26. Implement the ability to drink buff potions while being mounted or at least seasonal and for-fun beverages such as wines, beers, and malts.
27. Add a quest reward for 100 coins of ancestry; you get something special. Food buff or something. Plus the respective achievement.
28. New quest chain, "The Rare Killer", and its associated achievement, where you evidently have to kill every rare mob in the game. Give a cool reward, like a tabard.