Wandering, following road surface variations, and darting around are usually signs of insufficient toe-in. An alignment, following the 2013 procedures and specs (toward the tight side) and using the tools developed for that job, can improve things in most cases. There can be other factors. Faulty or tight steering components, such as the batch of bad ball joints, could enter into it. Tire pressures matter...16-18 up front seems to be best with the 2013s. Finally, despite thinking you are not overcontrolling...you probably are. We all did so at first...maybe for 1,000 miles or more. On a bike you normally react to a gust of wind, and automatically compensate. It is hard to let the wind move your upper body around and not move your arms at all. The slightest steering input moves a Spyder around. Bumps are similar, any motion transmitted to the handlebars results in a reaction. The Spyder has no gyroscopic stability like a 2-wheeler, so it tends to move around more than you are used to. Steering sensor calibration can enter into things, too...which is a real possibility if there is a tendency to continuously pull to one side.
My advice...have the front end carefully aligned and inspected by a competent shop, check your tire pressures, have your steering sensor calibation checked on BUDS, make a conscious effort to loosen your grip and not react to road and wind variations. Have an experienced Spyder rider try your Spyder, ride another Spyder yourself if you can (2012 or earlier or a dealer demo). That should tell you whether yours is significantly different. I hope you find the answer to your difficulties soon.
