Not really sure this would work.
Now that I have been given the perameters of what I can work within, I have a few ideas.
Is it possible to introduce new spells into the game? The aquisition of the spells would be the quests themselves.
Keeping to the historical perspective. It was usually a general rule, that spells beyond third level, the characters (and the perspective players) would go on quests to aquire new spells of a higher level or create new spells from the 1st to 3rd level spells given to them.
Not trying to beat a dead horse here, only trying to look at the idea of the runes a bit differently.
The runes, though not physically runes themselves, are only artifacts of significant elemental wisdom and power. Perhaps the runes, though physical are only markers on the path to finding said artifact of the corresponding element.
Such things could be used to introduce new spells, such as, invocations, transmutations and conjurations. Maybe even divinations.
Like the artifact, Rod of Seven Parts. Each elemental artifact could be like the rod.
Earth would have seven components that would enable a character to make a smiths hammer that could be used to smite constructs and give certain spells of an earthly nature to its wielder.
Fire, components to making a suit of armor
Air, components to making a great bow that with each arrow fired would create a rain of arrows against an opponent.
Water, components to making a spear, that could summon forth storms of lightning or the ability to move from one shore to another.
I am also given to wonder if this idea would even work.
Each component for each artifact would have its own innate power. I will have to figure out what would be a sutiable component and possible innateness (not sure if that is a word*shrug*) for each component of the given artifact.
Any feedback would be greatly appreciated.