I agree with Jay -- your backrest looks a little high for rolling or a paddle-float re-entry.

I stripped my back rest per Nick's instructions, but I stripped it on a curve to make it a little more comfortable. No padding. If the curve is right you dont need any padding. I find that I am leaning forward most the time when paddling, so all I need is a little lower lumbar support. A nice, low seat back is fine.

Entering and re-entering the kayak can put a lot of stress on the seat rest. The wooden padeye on the back of mine broke during my first paddle-float reentry practice. you might want to put in a stainless fitting there, but watch for chafe against the coaming.