As for problems associated with what can be "observed and described," I think I may have anticipated your point and tried to answer it here, at post #249.
Why does biology have to be a "'softer' science?" Supposedly biology deals with the biggest questions that can possibly be asked; and you are suggesting that as a scientific discipline, it cannot become more rigorous? If so, why not?
I suggested that it cannot be simplified and abstracted as pure mathematics. I imagine it would be nice if we could. We could do things like predict all the effects of new drugs, just by running them through an equation. But it cannot be that "rigorous", because we don't know nearly enough to make it so. If you have any concrete suggestions on how to change it all so that we do, I'm sure that would be a very intersting discussion.