Rune binding query

As far as using opposeing runes ,I think that going to be a cult to cult thing. For those that have previous version of Runequest should remember certian cults prohibited its members from casting certian battle magic spells. Like light cults could not cast darknesswalll ect. But then some darkness cult could cast light spells cause their God defeated certian fire/light Gods and stole their runes.
and as for what happens to the rune after you master it. I was thinking in my game it becomes like a tattoo on the body, at least in some cultures. It been mention certian creature like dragonewts do tatoo runes on their body but thats one idea.
After more though( My heads hurting ,Im to old to think much) On Runes and how to interpet what it says. Im think that once you get the rune you keep knowledge of it forever unless something major hapens. But to cast a rune spell you need a fetsh similiar to those used to cast spirit magic und RQ3. So once you learned metal and say bladesharp 3 you cant lose the Knowledge of the metal rune, but you can lose the object you have inscribed bladesharp 3 on. Im guessing that what the author may have ment.
And as far as getting the runes themselves ,I think it should be varied and not just be found objects. for example to get the fertility rune, have an Earth priestess watch over a certian Holy Fruit tree that bears 12 magical apples each year that if eaten grants the fertility rune, and make it so the Players then have to convince her that they should be one of the 12 people. for the Storm Bull They could have a magical sword that each season grants the metal rune to the most worthy person who does not already have it. The most worthy person being the one who brings in the most powerful chaos monster by himself.