1. Mini DV can be HDV which is HD footage 1440 x 1920i.
2. Too many types without more info like a camera model.
3. These can be downloaded to iPhoto or similar over USB.
MiniDV or HDV connects with a firewire cable.
The hard drive camera will use a USB cable and FCE>Log and Transfer if it's standard AVCHD, if not then you have to jump through a few hoops depending on the camera and type of footage it produces.