Do you still need to have a tape in your camera while you use this?

You can set the Firestore to "local" control mode and just hit the "REC" button and the Firestore will record anything you can see in the VF or LCD- wether you are recording or not on tape...however it does accept most camcorder's Rec and Stop/Pause commands via Firewire if you do plan on using tape- but check your model for "firewire" control.