When concluding an employment contract with Ilyushchenk

When concluding an employment contract with Ilyushchenko on working as a manager, the director proposed to include the following conditions in the employment contract: on establishing a probationary period; on the termination of the employment contract in the event that Ilyushchenko refuses to go on a business trip; about the obligation of Ilyushchenko to use annual leave only in winter time, to fulfill the duties of the department head during the absence of the latter, not to work part-time with another employer. By agreement with Ilyushchenko, an employment contract was concluded.
Are the conditions of the employment contract valid? What requirements should the content of an employment contract meet?