Thanks for mentioning my post!
One remark, from what you said in your guide.
It is better to register using an username and password (email can be bogus/nonexistent, they don't check), if you intend to play on mobile too. With keychain login there is issue on mobile (on Android), or there was when I tried it and I had to go through support to change my login method from Keychain to username and password. Eco recommends username and password too.