It was Fall of 2010 when I last rode the 2011 68 Strada. I wasn't using the Radar bindings yet and can't remember settings but felt too much speed and not enough turn. So last year used the 67 Strada with the Strada boot 1.5 holes forward of stock. I think the unique bevel design allowed me to get away with being so far forward and also increased the surface area like a narrow 68. I'm on the 2012 68 now and started the season with the front boot in the middle and moved forward 1/2 hole after the water warmed up. The new ski is a little more forgiving and my scores have been more consistant.
One back probably won't help your off-side on the 2011 68. You can try moving forward but ultimately I think you should get a 2012.