Can he buy meat from a non-Muslim butcher who says that it is halaal?

What is the ruling on eating local chickens when one does not know how they were slaughtered?

The reason why it is forbidden to eat meat without draining the blood

Meat slaughtered by a mute person

Eating meat slaughtered by a person who has moved from one kaafir religion to another kaafir religion

Workers in the abattoir are followers of a number of religions

Thrown into boiling water when they are still moving after being slaughtered

Leaving blood in the animal after slaughter

A slaughter-house in which some of the workers do not pray

Is it sufficient to mention the name of Allaah over any meat?