Quests are controlled by the scripting engine and the only way to make this would work be to expose the variables used by the scripting engine, but this would not be user friendly and the typical user would get no use out of it whatsoever.
Seconded. Exposing the raw Rete databases would likely be no gain for the average user as you'd have to know the scripts that work with said database for it to be of any use; additionally most quests track their progress in many separate databases, and most of them are shared by hundreds of other unrelated stuff. Changing them properly in order to progress some quests is almost an attempt in futility.
Not to mention that most scripts do far more than just messing with DBs, they change alignments, teleport NPCs and do other stuff that then you'll have to replicate.