I'd keep the handlebars just cuz putting on flats means changing out the shifters would mean extra $$$ for fewer hand positions (drops for the wind, climbing, etc.) I would swap out them pedals though, but that's just cuz the ones you got on there now look like the testers they use at bike shops. How about a waterproof pannier or two for carrying all your stuff and grocery getting?

edit: Maybe some inline cross levers so you can ride the tops and be more heads up?