Speaker cable length.

The audiophile rule of thumb is that always keep both lengths the same. It is one of those things that has never been worth my while to test. It is easier to be safe. There may be many technical reasons not to do it. One is that electrical wire (non-single crystal) is made of thousands of small grains with boundaries and the signal is very slightly delayed by these causing smear. A while ago I actually read a scientific article on this… and it happens differentially across the frequency ranges. So the grains act like little capacitors. Anyway, you can see how across vastly different lengths you end up with different effects between the speakers.

Yes, coiling up wire puts wires next to each other. I am sure Transparent is shielded. I have had a coil or two here and their over my lifetime.
 

I hope this is helpful. 

I’m gonna go with the signal is moving at such a ludicrously fast speed that 12ft. differential will mean the same as zero. Just use the lengths you need to use, no more, no less and save your worries for other things like how the smoke particles getting into your gear is going to affect it.

I wouldn't worry too much in this system. The crossover components' tolerances would be far greater than any anomalies imparted by the additional cable length.

I am of the school of the shorter the ru the better, hey it is all subjective do what works and sounds good to you. 

@n80 different lengths of the same cable should have different resistance; in this case it should be a vanishingly small figure. Whether it’s an issue for your amp, let alone an audible discrepancy, you’ll just have to find out.