Well after you complete everything from above, then start a new game and play as evil, which is alot more fun than playing good. Its a pretty easy game to get a platinum trophy, but even if that isnt your goal, just to see the differences in missions and the powers are fun.
Plus that will then give you a gamesave to import for both Good and Evil playthroughs on Infamous 2. And the perks it gives you are really nice.