I recently noticed that the asteriskuser can log into FreePBX, even when it’s not listed in the Administrators module (which is enabled and functional).

My multipart question is:

Is the asteriskuser user mandatory?
Can I change its password from S3cUrEpAsS?
Can I use special characters in the password?
Can I block it from FreePBX web interface?

I’m using a vanilla asterisk / freepbx install. No trixbox or the like.