The thing with nations is quite difficult, chaps. On the one hand you don't want to ban too many nations, but on the other hand you want a game that stays running past 40 turns also.
So the banlist might not be what you would expect that does not mean things will work out that way too. Like Grudge said; veteran players are screened first and might not be allowed to play a certain nation, while a noob IS allowed to play that nation.
The banlist is merely a list of nations that NEITHER players are allowed to pick. And yes, Mictlan was an oversight.
The thing with stealth is that we currently banned all nations depending highly on stealth afaik and that includes TNN eventhough it might not be that powerful. This is for the sake of avoiding any arguments about stealth ("eventhough he has TNN -a weaker nation-, he STILL has stealth!"). See? The other side of the medal. That's what I wanted to avoid.
Wether to include CBM or not is up for debate still as far as I am concerned, David and Goliath was also played with Worthy Heroes and vanilla.
The ongoing discussion is wether you want noobs to play with vanilla first (and maybe a few small mods which don't alter gameplay too much) or get them into playing with the big often used mods right away.
I am in the 'go vanilla first' camp myself as I think you should first know how a game plays at its core to be able to understand what a mod has altered exactly. Reading a readme.txt or a changelog doesn't really help if you never saw it hands-on. But, like I said, this is up for debate and will always be. If the general wish for this game is to include CBM once we have players enlisted, we'll go CBM enabled.
EDIT Euarchus, welcome! You have been added to the list.