I understand your question only too well because I have asked it of myself many times. And by the way, it isn't 'innocent' it's loaded, but I'll skip that. My answer is simple. There is of course, a certain amount of assimilation. It's natural. Islam sees this as attrition. A great loss, a threat to its existence. If a muslim is not practicing his 'religion' he/she is apostate and that is punishable by death.
Assimilation is the greatest fear islam has. This is the first time in history that muslims have been required or able to live in the West as equals, not conquerers...thus, the imams in the mosques tell them we are filthy kuffar who will pollute them, they describe us as 'effluent from a sewer' and use whatever fear tactics proscribed in the koran in an attempt to keep their community apart from us. The Saudi wahhabi literature, which is delivered free to all islamic communities and bookshops, re-inforces their teachings. If you live in an area where this influence is not seen nor felt, it's not because the community are 'moderate' it's only that the clerics and the money, the literature has not arrived or reached them yet. It will.
Muslims can't escape islam. Mohammedanism was designed to hold its people captive.
http://www.frontpagemag.com/GoPostal/commentdetail.asp?ID=12226&commentID=260388
The above link should give you some idea of what the imams preach. This one is from Sydney, Australia.
You are as eloquent a street fighter for this cause of ours as I have come across...pick your fights well and keep on fighting.