I think in some fields achieving (c) is almost impossible - the n number needed would be too expensive for most labs working with animal models, for instance. (b) would be interesting, especially if it led to a culture where "failed" results are still worth publishing because they disprove something. I think (a) is the one worth focusing on first, since that seems the most achievable and would let you back-apply some of the other improvements at a later date.

Interesting. The idea that null results are not worth publishing has since the very beginning struck me as one of the most fundamentally flawed ideas in science. Interestingly, it seems to be very domain-dependent. In my field (astrophysics), null results are fairly frequently published, but I've heard that in other fields it's totally impossible to do.