What an excellent post and thought-provoking ideas. Thanks for the brain food! I went straight to buying Henry George´s book.
An issue comes to mind for me once virtuous rent is implemented: more people will have more money to spend, but that does not necessarily mean that personal choices will favor activities, products, services or companies that take better care of the environment. Humans end up receiving the rent form the internalized externalities, however the ecological services are provided by natural systems, not humans necessarily. So the question becomes: if the point of the virtuous rent -as you explain it- is to also regenerate natural resources and offset ecological damage and resource extraction, how can we tweak the systems redistributing the wealth so that this ecological regeneration does, in effect, come to pass.