I dont know about the Bulgaria thing (they might add it in the future) but to choose a different map you click on game options and in one box there should be a game type option where you can choose games different from 1990. However, there might not be games of some of the modes availiable but there should be different ones.

We have chosen some countries to be playable, Bulgaria might be one of the playable countries in the future, don't loose hope! might be more maps in the future!

Why can't you create more then just 1990 map? Well you can create a game with any map without the newest 60 players map, that map has been chosen to be generated once a while by the game. We want players rather to join the auto-generated maps then creating some themselves and not having them filled.

Moved to Questions & Answers.