If all faith schools closed then all the children attending them would need to be educated so the exact number of teachers would be needed somewhere. Its ludicrous to suggest that all teachers in faith schools are going to be unemployed and unemployable. Its a non arguement.
As for planning permission, it is granted on occasion believe it or not, a school near me is now a housing estate and change of use wouldn't necessairly apply if the land was still used as a school, but a free school or an independent school instead of a faith school. It wouldn't benefit the local children who don't get a place in a faith school to then not get a place at the replacement school.
I don't know what you mean by "Just run them according to the laws and morals of this country". They follow the national curriculum, they contribute over and above in terms of man hours and money, they don't go around poking poor people in the eye with sharp sticks, some (but by no means all) have ludicrous systems in place as a slection criteria but all oversubscribed schools have to apply their selection criteria and being able to afford an expensive house isn't a very moral method either. Faith schools aren't any more socially selective than anywhere else. Some faith schools have parents jumping through hoops and so do some non faith schools, often riding on an underserved reputation of being impossible to get a place at therefore 'the best'.
Are you suggesting that they don't hand the schools over, continue to pour resources into them but not have any selection criteria even though they are oversubscribed. Why should they? Should desirable non faith school also have to take all comers or should they continue as they are, taking from an exclusive catchment and charging £17 for a jumper and going on skiing trips just in case any poor people were thinking about applying.
You can't have it both ways. Either they become fully state funded and the state buys out the organisation that actually owns the school and, or they are left as they are, part state funded, part church funded, selective on the basis of faith, or they become independent of the state and dcs whose parents can't afford it will have to be found places in the state system. Being funded by the church and run by the state isn't going to happen.
I would agree (as the Bishops conference said) that admission should not be a box ticking excercise that allows 2 parent professional families to meet criteria that are near impossible for poorer single parent families. I don't know what they should be though. Admissions criteria have to be clear and I can't see Mr and Mrs cleaning rota and reader sitting back without a place whilst Mrs lone parent immigrant only goes to mass twice a month because the bus cost a lot and she works alternate sundays gets a place for her child.