I also want the router on the WAN for Internet, and only LAN-to-LAN traffic over the VPN.
After implementing the above changes, the router can browse the Internet locally, and the VPN Server can connect to the router.
However, even though I have configured the VPN server to act as a router (IPEnableRouter = 1 on Windows), and after adding a static route to a desktop computer behind the VPN server, I am not able to ping the router from the desktop.
If I revert the changes to the /etc/init.d/startvpn and /etc/vpn.user files, I can once again ping the router from the desktop computer.
It seems that the routing or the firewall is not allowing multiple hops to get to the router.