Mobs who should drop quest items 100% that don't:
Elishia Blackguard (Jaggedpine) - Head of Elishia Blackguard
Reynold Blackguard (Jaggedpine) - Head of Reynold Blackguard
Vaurien Sticklebush (Jaggedpine) - Head of Vaurien Sticklebush
Zed Sticklebush (Jaggedpine) - Head of Zed Sticklebush
Oobnopterbevny Biddilets (WK) - Live Enchanted Rat: Jar 1 AND Live Enchanted Rat: Jar 2 AND Live Enchanted Rat: Jar 3
a kly imprecator (Dalnir) - Dagger Hilt OR Jagged Metal Shard OR Sharp Metal Shard
an undead blacksmith (Dalnir) - Forge Hammer of Dalnir
dark librarian (Mistmoore)- Illegible Scroll
dark librarian ass't (Mistmoore) - Illegible Scroll
failed crypt raider (Kaesora) - Illegible Scroll AND Tattered Note
Mobs that should drop non-quest loot 100% that don't:
Garanel Rucksif (Unrest) - Jagged Band OR Dwarven Work Boots
Queen Nhyalia (Jaggedpine) - Cloak of Shimmering Water OR Dew Woven Gauntlets OR Dew Woven Leggings OR Dew Woven Sleeves OR Enchanted Dew Woven Circlet OR Guardian of the River OR Nyahlia's Nullifier OR Satchel of the Hatchling
inferno goblin torturer (Sol A) - Momento Box OR Turquoise Eyepatch
A Dread Wraith/Dread Wraith(CoM) - Ornate Rune Blade OR Ornate Rune Shield OR Brass Stud of Wonder
Battle Master Ska'tu (Chardok) - Jeldorin OR Nathsar Gauntlets OR Shai'din Revenant Bauble
Grave Master Zo'lun (Chardok) - Crypt Master`s Conjuring Stone OR Earring of Blazing Energy OR Engraved Di'Zok Deathbringer OR Hardened Bone Spaulders OR Wild Lord's Sleeves
Sorry, this is probably going to be a real ballache for you over something that the vast majority of the players aren't even going to notice is wrong! Probably really long post inc. :/
Apart from the Qeynos neck quest I haven't encountered anything that has broken a quest and made it totally unable to be completed as far as drops go, but that may just be down to pure luck.
I've completed the following quests on False that I can remember have issues (mostly loot based):
Jaggedpine Poacher Heads: Collect 4 heads from Elishia Blackguard, Reynold Blackguard, Vaurien Sticklebush and Zed Sticklebush in Jaggedpine Forest. Reward is Sigil Ring of Jaggedpine. The heads should be 100% drops from each of those guys but are not (although I remember reading in another post you didn't like the out of era Jaggedpine stuff so this isn't really the end of the world.)
Marsinger Plane of Hate questlines: Quests start with
everquest.allakhazam.com/db/npc.html?id=13766 and
everquest.allakhazam.com/db/npc.html?id=13767 depending on your class.
Due to the era that Hate is locked at, all the pieces from the 1st, 3rd and 4th quests are dropping but not the 2nd due to the "x of hate" mobs not being in the game. Again this is an out of era quest and even the 1st quest reward gives a pretty overpowered for the era Range item. The quest pieces for the 1st 3rd and 4th items probably should not be dropping rather than the 2nd pieces dropping.
If you were to add the items for the 2nd quest you would need to add:
Etched Sorcerer's Crest
Etched Soldier's Crest
Etched Knight's Crest
Etched Priest's Crest
Vengeful Dust (don't think I've seen a vengeance golem)
to the drop tables of (I guess) the "x of Innoruuk" mobs in Hate as they are the most direct replacement of the "x of hate" mobs.
If you were going to remove the items for the other quests would you would need to remove:
Minor Signet of the Dark Soldier (multiple creatures)
Minor Signet of the Dark Priest (multiple creatures)
Minor Signet of the Dark Knight (multiple creatures)
Minor Signet of the Dark Sorcerer (multiple creatures)
Abhorrent Powder (an abhorrent)
Kiraikuei flesh (a kiraikuei, possibly a greater kiraikuei although I don't recall actually seeing them in this version of Hate)
Ghast Fingerbones (an ire ghast)
Vampire Dust (a forlorn revenant, a forsaken revenant and I believe Coercer T'Vala)
And the following drops from minis and in some cases Inny:
Dissertation of Dark War
Compendium of Classic Torture
Tome of Dark Healing
Concordance of Black Magic
Applications of Suffering
Book of the Dead
Tactical Hatred
Teachings of Innoruuk
Texts on Pain
Writ of Agony
Interrogator's Badge (Qeynos neck quest 2): The interaction between an interrogator and Theodore Exanthem is totally screwed up. On hailing an interrogator he goes crazy and spawns Theodore on top of him who becomes unresponsive immediately. The way it should pan out is he should make you follow him to a hut with Theodore in and then tell Theodore "Take us to the location" at which point he should lead you to the druid rings I think where some mobs are spawned.
Researcher's Badge (Qeynos neck quest 3): Kind of moot I guess because the second quest is AFAIK unable to be completed in its current state but I noticed this because I saw the guy walking by and recalled I needed the items for a later quest.
Oobnopterbevny Biddilets should drop Live Enchanted Rat: Jar 1, Live Enchanted Rat: Jar 2 and Live Enchanted Rat: Jar 3 100% of the time when killed. As things stand he currently drops 0-3 of the jars randomly with the possibility for duplicates.
Crusader's Test of Betrayal (Iksar Khukri quest 5): At 7 PM game time in Firiona Vie, Tracker Azeal respawns and is meant to path to a cliff on the far east of the zone and then kneel before you are able to give him a quest item to continue the chain. In essence this is working fine except instead of pathing out of the city and over to the cliff, he just goes for a casual swim through the water instead and then jumps 100 feet up a cliff to reach his destination (lol). He also seems to refuse to kneel once he gets there but I may not have waited for long enough. Regardless this is only a minor issue and the quest seems to work fine other than that.
Visceral Dagger (subquest of Iksar khukri quest 6): There are three versions of a kly imprecator throughout Dalnir. Each one should drop a piece of the dagger (Dagger Hilt, Jagged Metal Shard and Sharp Metal Shard) 100% of the time. Instead they seem to have a shared drop table here and can drop 0-3 of the parts randomly. Additionally, an undead blacksmith should drop Forge Hammer of Dalnir 100% of the time. He currently does not either.
Crusader's Test of the Lord (Iksar khukri quest 7): In Castle Mistmoore, dark librarian and dark librarian ass't should drop their Illegible Scroll 100% of the time. They currently do not. In Kaesora, failed crypt raider should drop both his Illegible Scroll and his Tattered Note 100% of the time but does not either.
I think there's probably more instances of the loot bug happening that I've noticed but they don't come to mind right now and in some cases it may be happening but I got lucky on the drop and didn't notice because of it. Also undoubtedly it has happened for quest pieces whose quests I haven't been interested in completing. In fact, loot seems kind of weird altogether.
For instance, some rare mobs that should be guaranteed to drop at least their common drop sometimes drop nothing at all. The only examples I can think of for this are Garanel Rucksif in Unrest, inferno goblin torturer in Sol A and Queen Nhyalia in Jaggedpine but I know for a fact there have been multiple others. It seems like this is down to the same problem. I will keep posting instances of it as I find them from now on.
Thanks again for all your hard work on the server. It is a lot of fun.
EDIT 1: Updated info on a kly imprecator (khukri quest 6).
EDIT 2: Updated info on failed crypt raider (khukri quest 7).
EDIT 3: Added lists at the top of page for ease of use. Anyone who has found other mobs that don't drop the loot that they should 100% of the time, please feel free to post here and I'll add them to the list.