Hi Joey,
I'm a relative novice compared to a lot of folks here, but I can give you some observations I've had with a similar weight/spine issue using CX 150's.
If your bow is 50# @ 28" and your drawing 26.5" I would expect the CX 150's to be a little stiff, even cut 30.5" with a 125g point. I'm shooting a 52# @ 28" Griffin longbow (pronounced r/d design - not quite cut to center), and drawing the full 28" I can get good flight from a 30" CX 150 with 200 grains up front. I shoot up to 250 grain point/insert combinations with a 29.5" arrow.
Now I'm assuming your Super Kodiak riser is cut to center, which will let you shoot a little stiffer arrow than I can with my longbow, BUT, if you're only drawing 26.5" then you're actually only pulling about 46# to 47#(?) with a 50# @ 28" bow.
I CAN tell you from experience, that a poor release and/or shelf/quill contact can give you a false reading when bare shaft testing. I don't know much of anything about paper tuning, but it seems to me that both methods would be susceptible to the same types of errors.
As I stated from the beginning, I'm no expert, but I hope my observations can save some time and arrow woes. Getting good flight from a well-tuned bow/arrow combination has been quite a journey for me, but I found after much trial and error that my shooting was to blame for some early headaches I suffered through.
Good luck!
Curtis