Tom, I spoke to my coworker this morning about this. We are running View 4.0. We have a WYSE terminal that supports PCOIP and works great but the HP one uses RDP. The problem is that the "view open client" is only currently built to run RDP on linux, it's basically a live CD that loads linux and allows you to connect to a virtual desktop, and the HP client is a custom linux build. The portal uses the same View agent as the VMware View Client, PCOIP works great, so my only guess is you're doing it wrong.
Since the teachers are all remote how are they connected to the network? He said that every piece of documentation he has read specifically uses a replica server in the DMZ. I don't know if that relates to the VPN issue you are describing or what.
But seriously, if you want to speak to my coworker I can surely ask him, or if you're in the University area maybe stop by and check out what we have set up.