This is a little Diabloish, but there should be a larger variety of Charms. The chief one on my list is Durability. For instance, it seems fated that that really good magic item you have that you Saved and Loaded for until it had the right combo for you also has a lousy durability.
Also, this might be copyright infringment, but a certain combo of Charms gives you a specific object or one with specific qualities.
Last, but not least, pre-charmed items. For example, there is a point in Vetistis where you get a ring from someone that has been handed down from generation to generation, and yet it has no charms in it. Don't you think there would be at least ONE charm in it?