Most important technical aspects of speaker wires? Capacitance, inductance, etc...

Looking into speaker wires, and technical specs or construction stated by companies, has anyone determined, measured of figured out WHAT are the most technical parameters for picking speaker wires? Is it Capacitance, inductance, gauge, insulation, construction, material used, shielding, etc...?

I do not buy thousands of dollars in speaker wires, specially for my $5K setup, but within reputable speaker wire companies being Furutech, Cardas, Audioquest, Nordost, etc... how would one pick wires? Obviously listening is the only real solution, however, many have to be broken in, not everyone has the options of trial, and it's a difficult task to complete if you're looking at multiple manufacturers, and various brands within each.

One last question, the outer sleeves used on high end cables, are they at all necessary outside of looking nicer?
For 23 years I used Mogami Blue Neglex 2477 coax OFC 12 gauge to connect to my KLH Nine electrostats. 20 feet per side. I bought it cheap from my friend and local HiFi dealer - who received it as a sample. It was a 40 ft piece that I cut in half - cost was $40! SQ was excellent - never felt the urge to change for something else! 

I would consider OCC wire for your cable upgrade. There are quite a few cable manufacturers currently importing OCC bulk wire from Japan. The cable is inexpensive and sounds pretty amazing in any system regardless of the cost of the system. The best cable in any system gets out of the way and let’s you hear the components. The OCC cable gives the absolute purest base platform and gets you closer to true absolute transparency.

“OCC (Ohno Continuous Cast) is the name given to the casting process developed to help defeat annealing issues and virtually eliminate all grain boundaries in copper or silver with a unique patented process. The OCC casting method uses specialized heated moulds in order to draw a single crystal up to 125 meters in length. With only a single crystal in very long lengths, there is an unimpeded free path for the best possible signal transfer. Along with this superior single long crystal structure, OCC provides copper and silver with the least possible oxides and other impurities”.
Yes, that's why I am looking at Furutech bulk cables, the have both OCC and OFC cables that are premium quality and different gauges. They even have a very high end bulk cable with sleeves and all sorts of insulation just like the $1000+ cables, and hence my question as to what is really necessary.
Post removed 
“Copper is not a crystal element.” 😆 😆 😆