1) I personally have no objection, although I would rather that my daughter went to a school with a mix of faiths and ethnicities. I think it's healthier to have exposure to other ideas rather than to be insular, and as long as a school has respect for our convictions as well as other peoples' then why not? Obviously Shabina Begum felt the same way, since she wanted to attend a mixed faith school, but wanted her religious convictions to be respected.
2) What some Muslims do in other countries isn't really relevant; but in some cases yes, in others no. I am far more concerned with whether we treat other people with respect and consideration.