I know what you want out of this class but, I don’t think it is unique enough. You did a good job at re-skinning many of the paladin abilities but, that’s all you did you just re-skinned the paladin.

Perhaps take a step back and think what you want your spell sword to be. It may be better for you to create some kind of arcane oath for the paladin instead. The paladin already makes a good swordmage if you simply ignore the non-mechanical lore that surrounds it.