hello and welcome
it is hard to say without actually seeing your swing....
but opening your stance will give you and out to in swing (one of the causes of a slice) golf seem to be a game of opposites ie. you have to hit down for it to go up and you have to swing (for righties) in to out for it to go left (draw). so you want an in sqaure face to in path for the ball to go strait.
then, just opening your stance will complicate further things if you don't open your body (relationship to the target line) as well.
so i would say try squaring you stance. and try a more in to out swing see if that helps also you say you moved your right hand to the outside of the shaft make sure you move the left hand too if you want a stong grip, the v's should still match up.