You can set two different input sensitivity in the LR-16 menu.
Full-scale input (pad ON) Unbalanced, 20dBu, 7.7 Vrms
Full-scale input (pad OFF) Unbalanced, 8.2dBu, 2 Vrms
You’ll hava a same input sensitivity in recorder/interface mode as well.
If you plug USB storage device to the front USB connector, the back panel USB port (interface mode) will be disabled, so not possible to use as recorder and interface device in the same time.