unrelenting force is also super useful, i recommend just the single word shout, it'll help you interrupt enemy casters/archers while you close the distance. it can also be useful to interrupt enemy power attacks since you lack the ability to block. and the cooldown for the single word is extremely short.
i would avoid marked for death merely for the buggy nature of it, plus you're dual wielding, you already deal a ridiculous amount of damage.
Elemental Fury won't work on enchanted weapons (unless that's changed since I last tried using it). Aside from that, as pointed out already when combined with the dual weapon speed perks you can attack very, very quickly. Good for pure offensive.
Slow Time is also a good choice. It will allow you to move around the opponent and deal damage while dodging their strikes. A good defensive spell, aside from the cooldown being a tad bit long.
And Unrelenting Force. This shout is just useful for every situation. You can either use it to stop attacks with the lower power shouts, or knock enemies over with the highest one and just keep hitting them.