There still hasn't been a fix for any of the twinking related bugs.
The issues are mainly broken quest requirements and broken rare spawns which both should be trivial to fix.
Here's a list of the standing bugs I'm aware of (note that db.vanillagaming has faulty quest requirements. http://db.valkyrie-wow.org/ seems to have the right ones):
Glacial Stone (http://db.vanillagaming.org/?item=5815) and Dartol's Rod of Transformation (http://db.vanillagaming.org/?item=5462) are unavailable because of broken level requirements in the Raene's Cleansing (http://db.vanillagaming.org/?quest=1024) questline.
The whole chain should be completable at 18.
Gravestone Scepter (http://db.vanillagaming.org/?item=7001) and Arctic Buckler (http://db.vanillagaming.org/?item=7002) are unavailable for alliance players because of a broken requirement of the quest Blackfathom Villainy (http://db.vanillagaming.org/?quest=1200).
The quest should be acceptable at 19 and without having done In Search of Thaelrid (http://db.vanillagaming.org/?quest=1198).
Gold-plated Buckler (http://db.vanillagaming.org/?item=5443) is unobtainable because it's a drop from the Deadmines rare Miner Johnson (http://db.vanillagaming.org/?npc=3586) who never spawns.
Nightstalker Bow (http://db.vanillagaming.org/?item=6696) is unobtainable because it's a drop from the Razorfen Kraul rare Blind Hunter (http://db.vanillagaming.org/?npc=4425) who never spawns.
I assume the following quests are also bugged but cannot confirm it myself as I don't play horde:
Dangerous! (http://db.vanillagaming.org/?quest=567).
The quest should be completable at 19.
Battle of Hillsbrad (http://db.vanillagaming.org/?quest=527).
The whole chain should be completable at 19.
As for the broken quest requirements, could it be that every questline in the game should actually be completable with the requirement of the first quest in the line? I've also noticed there's a bug on Nost where you get a quest text popup even if you don't meet the requirements, but maybe the popup is intended client-side behavior for questlines and the actual bug is not the popup but the requirement? I cannot be certain of course as it was so long ago but I do believe to remember often ending up with deep red quests way too high for my level when doing chain quests back in retail vanilla.