I'm concerned about a couple things I've seen mentioned in several decisions, but never formally outlined in the submission guidelines; namely, minimum length and encoding rate. I feel that ReMixers should be aware that arrangements under a certain length (around 1:30 from what I've seen) are very unlikely to be accepted. Likewise for submissions encoded at 64kbps or lower. Or maybe it's already been addressed and I missed it.
I also advocate drawing a stronger distinction between the traditional and OCR definitions of "arrangement" and "remixing," as they are significantly different from each other. Although the OCR definition of arrangement could probably be inferred from the appropriate section, I didn't find any mention or warning against extensive sampling, i.e. traditional "remixing."
Again, if I've missed something, I apologize.