You can handle toe corrections with the OEM links but camber can be excessive if you lower too much. Remember you don't need as much static camber with the FRS/BRZ as gain negative camber as the suspension compresses.
Aftermarket links are more about correcting the camber and reducing geometry changes from high load cornering.
I wouldn't rush to zero toe with the OEM arms however since there's a lot of dynamic toe changes. With aftermarket arms that will hold the geometry more true you can go straight there
Thanks,
Phil Grabow