It now works for both the Registration form and the Forgot Login form. Is this the correct way?
Yup, that will change the captcha globally.
Is there a way to enable "CAPTCHA - Invisible reCAPTCHA" for the entire site (all Guests who aren't logged in), since the Login Module will be on every page? Is there not a benefit to doing this?
Personally I don't recommend enabling it for login form. Username and password alone are basically a captcha as is. I would suggest only enabling captcha for registration and forgot login forms.
I think I found it: under "CB Antispam > Parameters > Captcha > Legacy". Wow, lots of settings. Love all the features here, especially the "Notify User".
Yup, that's the correct location to enable login captcha.