I love the game and I find it very well done, I like the trading system and the speed of the game, I have few suggestions that can be taken into consideration.
1 - Can you add the option of playing with friend with a random user online instead of an AI ?
(So when you are missing a 3rd player you dont have to play against an AI)
2- Quitters and some players are using the connection lost to quit the game for them not to lose KArma, As I live in a country where we have power cuts, I know that we face alot of connection loss, I dont know what you can do for people who use it to quit games.
3 - Can you add a blocked list so people can block userame that they dont want to play with.
4 - or you can add a report button where players can report thers for violations.
A suggestion to the developers for issue two: Can't you do some simple statistics on the number of connection issues in a particular country? The country can be derived from the ip address. The average number of dropped connections per player per month, and it's standard deviation can be derived from the visitors to catan itself.