I wouldn't bother with block perks for weapons, while shield wall and the bash perks work with one handed weapons, you can't block or bash with a spell equipped, kinda defeats the point of spellsword. Better spend perks on dispatching enemies more quickly. Kill them fast, no need to block.
Daggers work best with that tasty sneak perk, nothing wrong with a sword, good enough for Elric and Gandalf, I think it's just D&D legacy says mages use daggers.
Dunmer? Hope you are sticking with fire-based destruction. Don't have to, do what you like, but you know, tradition. Also, though they have a distaste as a general rule against necromancy unless it involves ancestors and tomb guardians, they have a tradition of dealing with Daedra, more since the fall of the Tribunal and the reinstatement of the Daedra in the temples, and a bit of Atromancy wouldn't hurt a Dunmer Spellsword in the slightest.