Having the g0/0 with ip nat inside is not an issue. NAT is not being applied since it isn't traversing inside to outside so don't worry about it. The router will simply route (without NAT) the traffic to 192.168.0.12 where the traffic will be NAT'd.
Try changing the route to this:
conf t
no ip route 0.0.0.0 0.0.0.0 FastEthernet0/1/0
ip route 0.0.0.0 0.0.0.0 dhcp
See if you get an IP next hop on the default route via f0/1/0 with that command. You might need to shut and no shut the f0/1/0 interface after changing the route.