Splitting Internet and local traffic

Hello Community,

Requesting some guidance with my XG125 remote office firewall.

I have a XG210 at our head office on 192.168.10.x network.
I also have a XG125 at a remote office that has SSL_VPN over NBN Internet connection back to the head office.
The remote office also has a wireless link back to the head office.
The VPN tunnel is slow and for internal traffic (90 secs to copy 100MB file / 40 secs over wireless).
For this reason I want to direct Internet (http/s) traffic through the WAN and local file traffic through Port3 which is linked to the network switch on the wireless link (192.168.10.x)
The XG125 at remote office is providing DHCP (192.168.7.x).

I have 3 Zones:
Zone 1 - Type LAN, All other ports as members
Zone 2 - Type WAN, Port2 as only member - connected to WAN modem
Zone 3 - Type LAN, Port3 as only member - connected to network switch

In Interfaces, Port3 (link to network switch back to head office), should the IP Address be local (192.168.7.x) or head office (192.168.10.x)?
In Gateways I have the Internet gateway as well as a gateway for the wireless link - should this local (192.168.7.x) or head office (192.168.10.x)?
From here, should I be using Policy Routing or Firewall Rules? and how do I configure those?

Remember, there is a SSL_VPN which I basically do not want to utilise, however I would like to retain it for failover and remote access from head office to the remote office.

All advise appreciated.