Can Simple CRM write documents automatically?

Not really automated. What you're asking for is direct mail. This is a function related to office suites, not CRM.

What you will do is select the contacts / companies to whom to address these documents, via the module of center of interests which makes it possible to carry out requests.

Then, from Simple CRM, you will export these data in CSV format (CSV = an Excel compatible file).

Finally, with your office suite, you will make a direct mail using this CSV file.

To learn more about direct mail, please search Google or your office suite's online help.