1) Teamviewer.com: Remote control any computer or Mac over the internet within seconds or use TeamViewer for online meetings.
2) Because when you use the manual button it's running the cron job manually, using the folder it's in. When you are using the cron job it's using the url you have there and using the root url / etc to send the email relating to your issue.
3) it's a special tag which does it which is why you can't set it.