Hello,

I don't understand  the "servicemanual" much.

Is there any way to make a user who has access to only download files from one specific folder ? 

Yes, it is a very basic file sharing feature. You can use our Group Account feature, which is free with 1 sub-user license. First, create a sub-user; then create a folder in your main account. You can then share the folder with the sub-user and set Read-Only/Download-Only permission.

To create a sub-user, just log on to www.DriveHQ.com and click Group Admin (on top, or from the DriveHQ Start Menu). To share a cloud folder, just right click on a folder then select share. You can share different folders to different users/sub-groups with different permissions. Sub-users can only see/access the folder(s) you shared with them. They cannot access your account and cannot see your other folders/files.