If you read the first 4 lines of the first wiki link, you will learn alot about cron.
I did mis-word slightly, it would have been more clear to say "Generally, if the script will run to completion from a manual start it will also run to completion from a cron start. "
If you configure it to do so cron can email you, either every time or just on error output.
Please review the previously linked pages, most likely many of your questions will be answered.
The key words in the TOS portion of the discussion seem to be
so find the API Documentation and see if what you are doing is expressly permitted, otherwise this is something andrewf deals with everyday so I would recognize his words are pretty darn credible.