If you open an online file from DriveHQ FileManager, edit it, just save it, the file will be saved locally to a cache folder and then sync-ed back to DriveHQ FTP server. This is a more secure and faster way than saving files directly to DriveHQ FTP.
Note if you save a file to an online drive or FTP directly, when the network is slow or disconnected in the middle, your application or PC could become non-responsive; you could lose your data.
DriveHQ FileManager is much more reliable and much faster. You will never lose data because of network problem. You can also setup folder synchronization between a local folder and a remote folder.
You can use DriveHQ FileManager or DriveHQ.com website to share a folder. Just select a folder and click on the Share button in the toolbar. You can set a permission when share a folder; you can also edit a share after the share has been created.