Lol thanks. I tend not to write well.
Well I'm from UK so the whole America thing p's me off. You are right that it is difficult to assimilate, however you look at most muslim women and they do not wear the niqab (In UK). In the same way when going to an Islamic country you shouldn't be showing off your cleavage and wearing tight clothes, but cover up out of respect. It's about meeting middle ground. They can wear a Hijab, but not a Niqab, we can cover up a bit. It goes both ways.
You're also confusing conquering a culture with assimilating with it. Europeans completely raped out the Natives, with intent to do so, not to settle with them and smoke pipe :P.
Take for example my family (I was born in UK). When we came, we learned the language and culture. We lived similar to the English but have kept the most important aspects of our own culture to ourselves. I dress mostly in western clothing, but my mum still dresses how she used to and as long as it doesn't affect her job, she should be allowed.
For a Sikh it is compulsory to wear a turban (or have it tied back i think). Unless it made a difference to their job, they should be allowed to wear it. I know there was controversy when they were not allowed to join certain policing/army positions because there was no protective headgear which allowed them to keep their turban. They have accepted this and you don't see them making as big a fuss about it (except for a couple of oddballs).
Forgetting that you should try and assimilate with a country which is open to your beliefs, at least when working you should abide to company policies, especially when they do not infringe on your rights.