No, depending on the nature of the misconduct or performance issue 1 warning may be sufficient.

No, unless the employee is not fit for work. The Fair Work Act states that an employee is only entitled to use personal leave in circumstances where the employee is not fit for work because of a personal illness, or personal injury, affecting the employee or to provide care or support to a member of the employee’s immediate family, or a member of the employee’s household, who requires care or support because of (i)  a personal illness, or personal injury, affecting the member; or (ii)  an unexpected emergency affecting the member.

You must not select an employee for redundancy  due to illness, injury or because they are on worker’s compensation.  However, an employee is not protected from redundancy simply because they are on worker’s compensation.  If a decision is made to make an employee, who is on worker’s compensation, redundant you must carry out the ordinary process that you would for example meeting consultation requirements prescribed in Modern Awards and Enterprise Agreements.

No, the role of a support person is to listen only (regardless if the support person is a lawyer, fellow employee or family member).  However, most Enterprise Agreements and Awards entitle Union Officials and Delegates the right to represent an employee in disciplinary meetings which would include asking questions and speaking on behalf of the employee.