Unless you instruct OpenVPN to push a default gateway, only the network you specify when you setup the tunnel will be accessible through the VPN.
Since I'm with XS4all I have WebTV and native IPv6.
So I'm pushing routes to the webtv network in addition to the local network. All other traffic remains outside the tunnel.
Since you want to send all traffic through the tunnel you have to push a IPv4 default gsteway. You can do this in the tunnel setup.
To have IPv6 everywhere I push a IPv6 default gateway always. But as you do not have IPv6, don't worry about it.
The only thing you have to do on the PFS box is to make sure that all traffic is forwarded through the other OpenVPN tunnel.
In my ignorence I assumed it was an IPsec tunnel.
As said, with an Atom processor without HW encryption I get 60Mbps.