4) no, it recognizes when you make a change and replicates that change on the target drive.

for the rest you need to be more specific, There is Active Copy (web interface) and backup utility which is only available on a local machine.

Active Copy deals with pogoplug drive-pogoplug drive interactions only.

Backup utility is a one way sync FROM your computer TO the pogoplug.

These are not interchangeable. The information for each backup utility is hosted on each respective computer