Canoeing may offer more scope of activity, for the "ezwater" stuff. I find that the relationship with the paddle blade is closer with a t-grip canoe paddle, and there's something about the crossing strokes, once you master them, which is absent from kayaking. (Although EJ and Scott Shipley use crossing strokes in kayak, not in races, but to improve paddle and boat control.) With similar hulls, kayaks have a much easier time getting back up and into holes than c-1s or open boats.

When it comes to the small boats needed for creeking, slalom, or playing, the disadvantage of c-1 is the uncomfortable low kneeling position. With open boats like the smaller Esquifs, the paddling position is a bit higher, but you will take on water, and when you roll up, a lot of it will be in the boat. And the open boats do not have the shape needed for all the play moves possible in a k-1 or a kayak converted to c-1.

You will convert to open boat only if the single blade paddle quickly makes better sense to you than the kayak paddle. That will depend on you.