There are several issues in there all run together, it seems to me, but I am not going to do a long thing right now, merely to note that history teaches that there are far too many employers who do not have any benevolent interest in employees, and who if left without the spur of the criminal aspects of Health and Safety law would choose to ignore their common law duty to employees (an implied term of the employment contract) - concentrating solely on "the bottom line".