Interesting and laudable. Honestly, your list of "criteria for success" looks a lot like the one we are using for our commercial ELN (CERF by Rescentris Inc). Our product also puts a strong emphasis on semantic relationships and metadata in order to try to make a more useful product. This is not surprising since our company is made up mainly of life scientists who (like you) understand the importance of managing different kinds of data in ways that make sense to human scientists, not just database engineers. We should talk. Feel free to contact us.