I have suggested #2 before: Just like Heal Mastery [which is utilised by all heal type charms], Elemental Mastery should exist for all types of elemental casting charms [Fire, Ice, Earth etc].
Some game mechanics would have to change if I am correct, those using say cold element 5%, also gain a defensive manner vs those types of charms. As for theorycrafting here, maybe they were introduced to implement them for Duels... which Paul has not made any effort in fixing since his last few updates.
Anyway, goodluck in what ever he may or may not change.