hi Ramana,
1.Its not recommended to placed multiple files that match the search pattern of the file event, the reason being, the event gets raised multiple times ("pending" status). The jobs dependent on that event will be submitted mulitple times, unless thats what you want.
To answer you question, yes the file event should move the file to a different directory if the option to move it to a directory is selected, and the directory exists, and the platform agent user has write access in that directory.
2. Which non-SAP jobs are you talking about? there are plenty. For types of CMD, *.sh, *.py, you can use proper error handling in your script to throw error, for example, you can use %errorlevel% check or/and set exit code in batch scripts in CMD.
3.Go to Monitoring-->Monitoring Tree-->expand system and dig through Database to check the tables. You can check the tables at the DB too, the tables have "JCS_" as prefix.
If you are looking for information on tables, the admin guide is the best place. You can download the admin guide for your CPS version from the "i" information button located at the top right corner.
thanks
Nanda