What obstacles are there to playing a noneuropean minor ?
Even if you take a fully functional minortag (there are a few special for testing purposes) there are some things hardcoded in the game that depends on the region (check your province.csv) where the capital resides. For instance, takeing a European tag and placing it in the Indochina region to play Japan will make it impossible to buy buildings. There doesn’t appear to be a way to change this either (though looking into the fantasia scenario could potentially give a clue).