At the relatively low frequency of audio signals - usefully 20 KHz and lower, the cable impedance (such as 75 ohms often used in video) is less of an issue. I would still use the same length and type of cable for each channel. So, as an earlier post here said, using video cable for audio is acceptable; using audio cable for video isn't. And just like any cables, you may hear a difference between different cables in the signal path.That is, some perceive a difference between various types of audio cable, so some may perceive a difference between various video cables used for audio. If you subscribe to the theory of cables that cost as much as Emotiva equipment, then I wouldn't substitute.
Summary: 1) Again, same type and length per channel for any cabling. 2) Shielding is the biggest issue in low level signal cables
Turntable: Technics SL-1200MK2 with Ortofon OM2 Blue Reel to Reel: Pioneer RT-707 CD: NAD 515BEE