1.14, your Current Occupations
his wife can click Other, and write that she is a housewife
his children can click other and write that they are student
2.1 Major Purpose of Your Visit to China
his wife click Other, and write that she goes to China for accompanying his husband
6.2 Relationship to the Applicant, in principal, the application form should be filled by applicants, your boss or wife can fill the application for their child, then the relationship is parent. You can't fill the application for them.