I think you're onto something. It was already stated by Matt10 that pass coverage slider is inverted and I confirmed this with resounding evidence after just one game of testing.
I just played three games to test the pass accuracy slider and can confirm that, too, is inverted. I completed 55 percent of my passes with pass accuracy at 0 and just 44 percent with pass accuracy at 100 (all other sliders at 50).
Also, I can confirm that RB ability slider works properly, at least for CPU. I jacked it up to 100 for CPU teams and the CPU ran wild like never before (I also had run blocking slider set at 100, so I'm not sure if that's inverted, as you indicated).
I will test the other sliders in the next few days.