From the ePO point of view, all you need to remove is the AgentGUID value. You can remove the MAC address and key entries, but there's no need to do so as they'll be recreated when the GUID is.
See your ePolicy Orchestrator Product Guide document (for whatever version you're running of ePO). https://kc.mcafee.com/resources/sites/MCAFEE/content/live/PRODUCT_DOCUMENTATION/ 21000/PD21812/en_US/epo_450_product_guide_en-us.pdf for 4.5.
Page 66 details various deployment methods. For image based methods it advises
"Administrator creates an image that contains the agent and deploys the Deploying an image containing the agent (Windows)
• Removing the GUID and MAC address allows the agent to image. Before creating the image, the generate a new GUID and MAC
address upon the first agent-server communication. administrator removes the agent GUID and MAC address from the agent
section of the registry. • Failure to remove the GUID and MAC address results in "sequencing errors" from the multiple identical systems"
Page 72 details "Including the agent on an image" but doesn't talke about MAC address removal at all, just yanking the guid by wacking
HKEY_LOCAL_MACHINE\SOFTWARE\Network Associates\ePolicy Orchestrator\Agent\AgentGUID
I don't recall stressing over removing MAC addresses in our deployment.