I love all of those ideas. I think the fundamental problem is that the renewal rates are far too low for domainers. For example, if you are selling a prime piece of land, the taxes are equivalent to the value of the land. Thus, encouraging the owner to either sell it or use it. A domainer selling a domain for $50,000 is basically paying the same renewal rate as person selling a $10 domain. This encourages them to hoard domains and wait years and years for some idiot to overpay for their domain.