I played a Sorc from 6th to 27th level, we just beat a prismasaurus in a cave this evening.
What? where would you put that encounter?
Anyway, it's a weak class, and the "talk to the hand" reaction they get from Quicken Spell is a detriment that overshoots any attempt to balance the class. I like your idea a lot, but I think I'd go with something like...
• 4+Int skill points
• Applying metamagic feats requires a move-action, not a full round. This make quicken spell almost as pointless, but not if the Sorcerer wasn't going to move more than 5 feet in a given round. There would be no way to decrease this requirement, save for maybe a PrC, sorta like Incantatrix.
• Some spells should have their Sor/Wiz level split likewise. Some spells are more Wizardly, IMO, and could use lower levels for Wizards. Analyze dweomer, for argument sake, could be Sor/Wiz 6th/5th; or you could lower some spells to better suit themselves to Sorcerer work: cone of cold Sor/Wiz 4th/5th, polar ray Sor/Wiz 7th/9th... or something else to your whim. It would keep the list together (unlike Monte's revised sorcerer spell list in Eldritch..) and still allow for diversity between the two classes.
So, all that as well as your Eschew Materials revisit, now that I've seen it. Nice work, btw. Good stuff.