Right clicking the vApp itself, gives power state options for the entire vApp. Stop and force stop.
If you go into the vApp itself you can shut down the vApp
Otherwise, you have to perform actions on the individual VMs instead of the entire vApp.
"Both of which undeploy the CIvApp which means the vm's lose their external ip addresses if they obtained by an IP Pool."
if this matters, why not just enable the ability to keep the external IP consistent.