I don't know about the map problem, but are you trying to load the races from the .emp files, or are you using the "add random computer oppenents" option?
The existing .emp files will no longer be valid when you add new racial traits, but you should be able to add in random opponents. Then when you are playing, select the "Players" button under the Game Menu (F2), set all the empires to human, and then save each empire under a new name when each of the turns come up. You can use these new .emp files for setting up desired combinations of opponents.
Just a bit of info, and if I'm in error about any of it, I'll soon be corrected
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