Kijanki, skin effect isn't considered significant at audible frequencies. At 20KHz it'll be less than 0.2db, which is truly insignificant in the context of real speakers in a real room.
Strand jumping sounds like quasi-technical mumbo-jumbo to me.
In your final paragraph I think you touch upon the real issue - it is all just a placebo effect? From a technical perspective the answer is that there are no audible differences between well designed cables for any purpose, with the emphasis on "well-designed". For speaker cables you must have sufficient gauge and conductor quality, a reasonable trade-off between inductance and capacitance, and proper termination can be important, but beyond that you are paying for mechanical characteristics. Complex layering, individually insulated conductor strands, and fancy woven outer casings can be expensive to build and terminate. The fact that these features may not improve sound quality over 10AWG zip cord is beside the point. If you want a very luxurious and expensive-looking cable it will likely be expensive.
I'm not so judgmental about expensively built cables, at least no more than I am about, say, expensive watches. They don't tell time any better, but if someone is excited about a $50K watch and is willing to pay, I say go for it. My 10AWG cables look like the cheap zip cord they are, and they do not look awesome like expensive 1/2" diameter Audio Quest stuff. But if you choose to believe that these fancy cables sound better, well, there's no evidence *at all* that these cables are better than zip cord. The differences you hear are almost certainly imagined. So is cable break-in.
Strand jumping sounds like quasi-technical mumbo-jumbo to me.
In your final paragraph I think you touch upon the real issue - it is all just a placebo effect? From a technical perspective the answer is that there are no audible differences between well designed cables for any purpose, with the emphasis on "well-designed". For speaker cables you must have sufficient gauge and conductor quality, a reasonable trade-off between inductance and capacitance, and proper termination can be important, but beyond that you are paying for mechanical characteristics. Complex layering, individually insulated conductor strands, and fancy woven outer casings can be expensive to build and terminate. The fact that these features may not improve sound quality over 10AWG zip cord is beside the point. If you want a very luxurious and expensive-looking cable it will likely be expensive.
I'm not so judgmental about expensively built cables, at least no more than I am about, say, expensive watches. They don't tell time any better, but if someone is excited about a $50K watch and is willing to pay, I say go for it. My 10AWG cables look like the cheap zip cord they are, and they do not look awesome like expensive 1/2" diameter Audio Quest stuff. But if you choose to believe that these fancy cables sound better, well, there's no evidence *at all* that these cables are better than zip cord. The differences you hear are almost certainly imagined. So is cable break-in.