I think the problem of items being overpowered isn't their atributes as such, but their number and avaliability - for example, gloves and bracers are expensive as there are only few (strong ones). [Let me again mention that I'd love to see craftable or alchemizable gloves and bracers - thank you
]. If these runes are not too strong (a little resistance each would do), not too expensive and not too easy to get, but still avaliable in large enough quantities (i.e. enough for everyone), I don't see a problem with that.
If these are to be evented, on the other hand, make a number of 20 or so and hold events which do not favor anyone - i.e. no spars, but rather trivia with mixed questions or rp-events.