I have a cheap chinese bucket boat that has a slatted (hard plastic) roll up floor. It sits just like yours does but it also sits ontop of an inflatable keel...it's more like a dingy without the flat transom. It tracks great!! I have an acquaintence that built one just like mine too but out of an old achilles or something. He did the same with an inflatable keel, put a jet motor on it and he runs it UP and down the New River and works great. Does yours NOT have a keel of somesort? That seems to be the key for these designs, and missing out on that seems to be a HUGE oversight in the engineering IMO. Speaking of design/engineering...I would be leary of those fishing seats holding up to much lateral movement and stress....ESPECIALLY in class V water!
Also is this thing a bucket boat (which I figure it is) or does it self bail? I ask because I'm not sure what gives you the impression that the NRS outlaw is like this boat? The oulaw is drop stitch floor (which won't track as well as an Ibeam) and is self bailing. I guess the boat is light and is part of NRS's "budget" line of boats....but still is lightyears ahead of scadden's boats.
Lastly, I assume you are not new to rowing seeing as how you have another boat, but could it be just figuring out the nuances of a different boat? Other than that try gluing on some skegs meant for an IK or SUP.