Thanks for review! As per your points they seems all quick and quite easy to implement so i think i'll publish a new version soon.
The Rune of Proliferation proliferate an elemental ailment, the only base runes that apply an ailment are fire [ignite enemies] and ice [freeze eneies], i'll add it in the rune description. All other runes have different special effect that cant be proliferated [like ealing, recouping mana, teleport, ...]
The only point i can not implement is the last one, combining base rune, because ... that's part of the game [NO SPOILER]. That could be a nice addition for a full game where the main quest is different.