This hand-wringing over hypothetical adopted children is disingenuous nonsense, it's the thought of Muslims in Britain that you're not happy about. How dare we have our Muslim ways, we should tug our forlocks and be eternally grateful for being allowed here.
Spare me the victimhood. If you indulge is socially distasteful practices (and lets face it, discrimination against children from extremely vulnerable groups is disgusting) you get the flak you deserve. You've argued your case clearly and when posters haven't agreed with you you've embarrasingly dropped into Islamophobia mode.
Islam is a pretty big established religion in the UK, so don't play the forrin victim "oh noos, I'm not allowed here' card with me. It's home grown bigotry as far as I'm concerned (and I have a personal interest in the rights of adopted children and I don't give a toss whether the bigotry against them is from Christians, Muslims or Scientologists or whatever). Sharia wills are not compatible with UK social norms when it comes to adopted children in particular or women in general, so they shouldn't be applied.
(On a side note if you want to see how Sharia family law running alongside English common law principles goes wrong, look at Malaysia)
If the Catholics or the CoE were arguing the sort of discrimination you are advocating they'd rightly get the same kicking. Every thread where a Muslim gets called out for their bigotry gets the 'You wouldn't say this about Christians' comment and every thread that attacks Christian bigotry results in "you wouldn't say this if I were Muslim' remarks. Religion poisons everything. You would be embarassed to argue your point had it not been religiously endorsed.