In order to troubleshoot an implementation, the professional should work with the organization's website owners to ensure that all JavaScript errors are resolved. This is because JavaScript errors can prevent data from being sent to Adobe's servers, which can cause the debugger to not show any data. For more detailed information, please refer to the Adobe Analytics Developer Professional study guide (page 8-9).

Access or store personally identifiable information (PII) like your email address. ID Service cookies are used to set and store a unique ID for your site visitors (the MID). This unique ID is used to track user activity on the website and to allow the ID service to collect and share data with other Experience Cloud solutions. However, ID Service cookies do not access or store any personally identifiable information (PII) like your email address.

To capture outbound links automatically without having to add custom code on the website, you can use the s.trackExternalLinks variable, which automatically captures external links without having to add specific click tracking code. However, you need to ensure that the s.trackExternalLinks variable is set to true before the s.t() call.
According to Adobe Analytics Developer documentation on trackExternalLinks, the recommended approach is to set the s.trackExternalLinks variable to true before the s.t() call on each page, as shown in the following code:
s.trackExternalLinks = true;
s.t();
This approach ensures that the s.trackExternalLinks variable is set before the call to s.t(), which sends the data to Adobe Analytics.
Reference:
Adobe Analytics Developer Documentation: https://docs.adobe.com/content/help/en/analytics/implementation/vars/page-vars/config-vars.html#section_59B0D9A9A11C4D0FAF2F6622C3D78420

The fpCookieDomainPeriods value determines the cookie domain on which the Analytics cookie will be set. For the domain https://xyz.co.region, the fpCookieDomainPeriods value should be set to 2. This will set the cookie domain to be ".co.region". Setting the value to 1 would set the cookie domain to be ".region", which would not be appropriate for this domain. Setting the value to 3 would set the cookie domain to be "xyz.co.region", which would also not be appropriate.