I thought I would take the opportunity to write down, as coherently as possible, my own views on several of these issues, as a physicist and cosmologist.
As a practicing physicist however, the situation is somewhat different. There, I, and most of the colleagues with whom I have discussed this matter, have found that philosophical speculations about physics and the nature of science are not particularly useful, and have had little or no impact upon progress in my field. Even in several areas associated with what one can rightfully call the philosophy of science I have found the reflections of physicists to be more useful.
Which brings me full circle to the question of nothing, and my own comments regarding the progress of philosophy in that regard. When it comes to the real operational issues that govern our understanding of physical reality, ontological definitions of classical philosophers are, in my opinion, sterile. Moreover, arguments based on authority, be it Aristotle, or Leibniz, are irrelevant. In science, there are no authorities, and appeal to quotes from brilliant scholars who lived before we knew the Earth orbited the Sun, or that space can be curved, or that dark matter or dark energy exist do not generally inform our current understanding of nature. Empirical explorations ultimately change our understanding of which questions are important and fruitful and which are not.
Interesting read... with a few errors in science. Well, kinda' big ones. But interesting read.