Using digital 75/50 ohm cables for analog

No problems - the "75 ohms" (or 50 BNC, or 110 AES) only applies to much higher frequencies than audio spectrum, for digital signals. You'll get debate on whether other non-coaxial geometries are more optimal for phono-level or line-level audio signals, but it will "work" fine for analog. 

75 characteristic impedance cable is better due to lower capacitance. Lower Er (dielectric constant), is better, because it shortens electrical length of cable, even the same length. important is also to look at central conductor resistance and shielding. Good analog cables have signal line resistance in the range of 100mOhm or lower. I have couple of reference double shielded, silver plated, balanced XLR cables with signal line resistance less than 0.008 Ohm! 

Thank you both for the information.  If I should be at 100mOhm or lower, it sounds like the 75Ohm cable is not idea though maybe not necessarily audible unless it's putting "strain" on the device it's connected to?  

75 Ohm characteristic impedance cable can have very small signal conductor resistance (few mOhms) between output and input. Ground / shield is a second conductor involved, which typically has much smaller than signal line resistance.