Actually, semi-anon games, where you know the players, just not which country they are, are pretty easily deductable. In high pot games (7000) we usually organize games as you wrote here, but also, by the end of the first year most of us know who is who, even though it's anon. For this reason I know some guy around who NEVER joins organized games, just purely anon ones.
Why I disagree with you is, I think my solution doesn't hurt any players while expecting them to password, or semi-anon a game does. (I know examples)
I have started MANY games, with 10day pre-game period to let players fill it up, and reamin fully anon. For these guys non of your solution is a solution.
About coding, I can do that.
About complecity tends to make things more likely to break, I have to agree. That's usually true. In this case I think this feature is "optional" meaning, for you for example, wouldn't cause any difference in the way you use this site. You don't have to build up a banlist, you don't have to leave games if someone joins, etc. So for anyone, who likes the thngs they are now, this solution wouldn't bring any change, any more complexity.