You should experiment with your couscous :) tomato and red pepper is particularly nice. Try sprinkling some pepper and lemon juice on it, too. I've heard lamb works well with it, too. Good luck on the couscous adventures! :)
Well, it's low in fat, cholesterol, and sodium and a good source of complex carbs.
It's quite similar to a fine grain pasta, and while healthy enough to eat, you still need to have variety in your diet to ensure you're getting proper nutrients.