I also think it's not practical for a lot of companies. As well, I know around these parts it is almost sacrosanct that one should have a Github, possibly blog, etc but there are many great programmers that do not have such a portfolio. I mean, many of these programmers are very good, deeply technical, and work on quite serious things.
As far as #5, you will definitely miss out on people there. Many people with real talent actually have bills to pay and companies willing to pay them without some trial project. I understand the reasoning here, I mean, wouldn't it be great if we could go a step further and get someone to work for free for a year before we start paying them, just to make sure they are in it for the "long haul."
#6, I have no problems with; it's quite reasonable.
Honestly, I have followed Atwood for years, how many of these things would he actually pass, besides the thing about being very public? - no ad hominem, purely tangential.