To delete a static shot, hold your finger over your shot's indicator. This will prompt the Action Menu to pop up. Drag your finger to the trash can icon, then release.
To turn off face detection, go to the More Options menu.
Tap the camera assistant icon to the far left.
Tap Find Faces to turn it off (it should go from white to gray).
You can return to the live edit view by tapping the down arrow to the right, followed by the X icon. Now no faces will be detected automatically.