1. Test game is linked from the main page before you register. A movie or short tutorial showing how the game is played would be fun, and you might suck people in if you gave them a hero and a dragon and let them rampage on some neutral armies. You could teach them about terrain bonuses and so forth in the process.
2. Making Warpedia more accessible would be nice. You could give KGB or some other dedicated player(s) the ability to work on it.
3. Small maps for 2 players would be great. I might try my hand at mapmaking soon
However, smaller maps won't make for faster games. The size of the map and unit movement speed are not the holdup; it's the time in which turns are completed. Smaller maps just make the game less balanced as players are too close to each other at the start. The real holdup is when you get a player like Razurandal who stops playing for 3 days in the middle of 20+ games without a word.
4. Achievements/badges are really hokey and overdone. But, they might work. I would prefer your "Ranks" idea, based on Ladder games.
5. Great idea. New players should get first move so they can experience the game.
6. Allowing players to be known as new if they want could be nice, but it depends on the response of the community. Banning them from Ladder games until they win at least 5 would be nice so we don't have people that join and quit during Ladder games.
7. Ranks should be visible soon enough thanks to Ladder games.
8. The term "hot seat" has a meaning, and this is not it. That would be if you played from one computer/chair by taking turns.