I have a recording studio. Can I use the VoiceLive Rack via and Aux send/return in my DAW?
Sure. The easiest way is to connect the unit as an analog effect in your signal path.
You can create an aux send that goes out to the VL Rack via the balanced Line input and then returns to your I/O device or mixer via the XLR or TRS stereo outs.
Using this method, the signal returned from the VoiceLive Rack will be layered over your dry signal. In the case of effects like Harmony, Reverb, Micromod, this may be exactly what you're looking for.
When using effects like Transducer or HardTune, you may want only the effected signal to be returned. The effect would then operate as an Insert. In order to accomplish this in most DAW software, set your Aux send to PRE-Fader and then turn the volume of your channel fader to 0.