Absolutely, integration and living in harmony is so important. Living in Luton there are so many issues. I am a practising muslim, I look the part too, beard an all and I live in one of the nicer areas of Luton. 25 years ago it was mainly white with the odd asian family. For whatever reason the majority of white people have moved away from this area and it is almost exclusively asian now. Why? I have no idea, honestly. My children now grow up without much integration and my son has zero white children in his class at school, this concerns me. Is it because of the asians ghetto mentality that this is now such a ghetto? I think there is more to it and maybe both sides are suffering from a lack of desire to integrate.
With regards to barriers, I will tell you a true story. Last time I watched Spurs last year I was racially abused by a Spurs fan as I walked to the ground, funnily enough I was with white friends and when the abuser realised that I was a Spurs fan he freaked. I haven't been back since because I will probably end up lamping the next taco who gives me crap like that unprovoked and I wont change the way I look because of a few idiots. Key here is that I see my white mates a lot less now as I don't go to football anymore. My point is that a minority of muslims damage integration and harmony and a minority of non-muslims do too. It is a two way story.