What is important and not important in cables is:
RCA interconnects. With a 10 000 Ohm load the center conductor is not at all important. It could be very small but then it might break. The interconnect should be a coax cable type with a heavy braided shield. With modern output stages, capacitance & inductance are of no importance.
XLR interconnects. Symmetry of the two central conductors is what is important. Their cross-section area needs to be identical, their insulation needs to be of the same diameter. Their placement inside the shield also needs to be symmetrical for the length of the cable. With modern output stages, capacitance & inductance are of no importance.
Speaker cables. Low total end-to-end resistance of the cable is important!. With modern output stages, capacitance is of no importance. Inductance is only a factor with a few loudspeakers.