If you remove users from the VirtualCenter domain, they lose permissions to all objects in the VMware Infrastructure and will not be able to log on again. Users who are currently logged on and are removed from the domain retain their Vmware Infrastructure permissions only until the next validation period (the default is every 24 hours)

Vmware doesn’t not explicitly restrict users from with same login and password from accessing and taking action within the VC.

If you rename user domain account, it becomes invalid in VC and same applies to group but before that(for groups only) you need to restart virtucal center.

Following activities can be scheduled as Tasks

• Change the power state of a VM
• Create a VM template
• Move a VM with Vmotion
• Create a VM
• Make snapshot of VM
• Customize VM
• Add a Host

This was the last part of the series from basic administration task,this pdf is in more details and end in 364 pages. There should be more information which be might be useful for VCP. I might add more to this series soon.