Magic weilding folk in the Lankhmar books always seemed rare, With the
Mouser knowing only a few tricks - no real reference to Runes either.
I did run a game a few years ago, set in Lhankmar (Using the old TSR stuff) with the RQ3 rules set (No spirit or Divine magic, only sorcery), and it went down well with the player.
I'm not sure how the MRG's rune magic will fit in - the settings magic always seemed pretty sorcerous - with very little that you could call being of Divine or runic origin. The Gods seemed very direct, rather than acting through a human agency.
The Skybolt... yep, personally I ditched the Chaos association and been playing it with a joint requirements either Fire&Death or Air&Death, depending on Sunspear or Thunderbolt style effect.
Overall, MRQ isn't too bad so far. I'ld have prefered a tighter mesh with Glorantha.
The rune integration isn't a bad idea, but the rules makes it feels a bit too contrived and I feel there should have been more detail.
Perhaps I would have liked to see something along the lines of:
If a character has the Death Rune integrated, healing spells, First aid are half as effective.
A character with the Undeath rune, shys away from the sight of the death rune.
A character with the illusion rune finds it hard to tell if someone is trying to swindle him.