You probably don't need a formal opening/closing meeting for your internal audits for the Agents & Brokers standard, but you will need a mechanism to demonstrate that actions have been communicated to relevant persons, to verify that these have been closed off and that corrective actions are effective.
Breaking the audit schedule down into sections of the standard can be a sensible approach, although for some you may find that the section is quite large to cover in one go so you may choose to split it into parts and audit e.g. half of the procedures in one go and the other half separately.
Some areas you may also need to audit more than once, as you'll need to do a risk assessment to define the audit frequencies (clause 3.5.1).
If you involve senior management directly in every audit then they may start to find it something of a burden, depending on how your schedule looks and how much time the senior team have available, but again this shouldn't be necessary unless the audit directly involves them.
You can readily demonstrate suitable commitment in this area by ensuring that internal audit performance is included on the agenda for the management review meeting(s) required under clause 1.1.3, and also any regular departmental and operational meetings.