My initial impression is that there are too many words on the homepage. The amount of content may scare people off. I'm assuming here that part of the purpose of this website is to advertise the relational viewpoint to a wider audience. I would probably recommend keeping the homepage to a shorter description of the purpose of the wiki and then provide a collection of convenient links to learn more.
We will also be using the wiki not only as a conventional wiki to define terms, but also as a general content management system. We need to decide on a good convention of how we will name pages that are not just term definitions.
But I like what you say!!! This will be a good and important project.