Lee,
First of all, the password is hardcoded and the option ist there to be
able to change it should it be ever required.
But regarding the RIP packets and the routes: did you create the proper
firewall rules to allow incoming IPIP from eth0 as described in 'Router
preparation' and a rule accepting incoming data from the tunnels (that
tunnel_local part)?
At least a firewall rule to accept RIP is needed for the tunnel interface.
That one was missing in the firewall setup instructions, I added it to
the instructions in the wiki.
Marius, YO2LOJ