No, in my setup for reasons of simplification, only LAN, WAN and Guest have a virtual IP. OpenVPN doesn't. Of course there will be not HA for OpenVPN, but I don't care.
VIPs are needed where you want a continuity of services when the primary is offline.For the businesses I work with, we want continuity of all services during reboots, hardware failures, etc. So every interface we have also has a VIP with it.As someone who has worked at businesses where VIPs aren't "always" used for all situations, it *really* sucks when you have a network problem, and you're troubleshooting and the lack of VIPs sometimes limit your options for troubleshooting. It also adds a lot of confusion because you're constantly trying to figure out what is broken by design (aka there isn't a VIP) and what is broken by fault.