I like the bonus spells and all the different things that vary by giant (dragon sorcerers and circle of the land druids should have this kind of variety), but it seems like it is trying to make the melee sorcerer without a lot of things that are good for melee. It is a strange day when the hill giant origin makes for a "better" fit than many other types. I might have given the fire giant flame blade, the storm giant thunderous smite, and ensnaring strike for the stone giant. Not sure what I would give the cloud giant.