The Apple keychain application will not let you remove system roots, it will only allow you to disable them. It will only allow you to disable them one at a time. For each one, you need to go through 3 UI panels and type your password. Is there a way to either automate this or do it all at once? I do not like Apple's current selection of system roots.
Backup keychain before trying anything.
Listing root certificates:
Just look in a dump for a names or SHA-1 hash values of certificates that you want to get rid of and write them down.
Now you can delete that root certificates using
For example you can delete chinese root certificates using this command: