If a nation were to carry out a census, the census would be in the major language(s) of that country. Regardless of whether now the parties to each language want to kill each other or if one group is viewed by you as being more alien than another, It makes sense for the implementation of public order and day to day life to use those both languages in say a census form or indeed street signs. I think this is just common sense not some extension of inclusiveness.

Question: if i am trying to set up a homogenous culture in a state at what point do I remove the bi-lingual aspect of the multiculture im replacing, do i remove it immediately or when the minority culture is too small to be a threat?

By this logic, every street sign in New York, Washington, Chicago, Los Angeles, Houston, and so on, as well as every road sign on every major highway in the United States, should be in Spanish, Korean, Chinese, Tagalog, Hindi, and Arabic as well as in English.

I think in the case of the us such a multi-lingual system is incomparable as standard english system was always the language. I set apart countries where people in different groups both are in large numbers and claim residence of a country. I dont see any problem with bilingual street signs in tel-aviv no more then I have a problem with them in londonderry. There is a difference between having multilingual street signs in say new-york than in say Israel.