IMO , no "religious" law should be recognized in secular court. If this cannot be respected by any group , that group should go to a place that observes religious laws as part of their government , like a "homeland".
It's sort of kind of true. In a way. British law allows the use of independent arbitration to sort out civil matters as long as both parties agree. British Muslims often agree to abide by the rulings of Shari'a law courts as their official arbitrators.
British law does NOT recognise Shari'a Courts as having any authority in areas of criminal law whatsoever, nor does it give Shari'a courts any power of final appeal.
It could be considered a foot in the door, yes, and many Brits do view it that way and find the idea very disquieting. I'm not too keen on it myself, as the precepts of Shari'a and the underlying concepts behind it are totally alien to British law and the British ideas of justice.
That's about the extent of my understanding of it, I'm afraid.
The difference amounts to two things, in Britain, I think: first of all, very few people know about the Jewish Courts (I certainly didn't!). And secondly, almost no-one sees British Jews as a threat to Britain's cultural identity, security or anything else. Furthermore, no member of the Jewish community has ever claimed that Jewish law should trump British law (Or if they have it has not been reported), which is sadly not the case with the Muslim community, where that kind of thinking is all too often vocalised.
Yes, they can. Any court of arbitration can be over-ruled by a higher court, and the right of appeal applies until you run out of higher courts to appeal to, basically. An arbitration court is very low on the chain.
That said, I should imagine there is considerable social pressure on Muslims not to appeal - but that is pure speculation, not fact.