Speaker wire size VS speaker size. Should bigger speakers use bigger wires?

Gauge 22  resistance is about 0.016 ohm/ft.  Your cable is 8 ft making it 8ft + 8ft =16ft.  16 x 0.016 ohm = 0.26ohm.  Assuming 4ohm speaker it will make  4/(4+0.26) = 0.94.  It means about 6% voltage drop resulting in about 12% power loss.  This power loss is equivalent to about 3.5% in perceived loudness change.  For gauge 16 cable perceived loudness drop will be 0.9%

On the other hand while 16ft of gauge 16 is 0.064ohm inductor in series with the woofer is at least 0.1 ohm.

Gauge 18 copper wire at 20kHz has still 100% skin depth, but thicker wire has slightly lower inductance.  I don't see reason going below gauge 12, but Acoustic Zen does.  My AZ Satori Shotgun has overall gauge 6.  It is divided into multiple isolated strands.  I suspect they wan't to avoid skin effect, but why gauge 6  (0.004 ohm/ft)? Perhaps they want to lower inductance.  Gauge 6 wire has reactance of about 0.9 ohm at 20kHz, 1ohm for 16 gauge - only 10% difference but it plays some role.

Assumption here is that thin wires will somehow change bass-treble balance reducing bass because of higher bass currents.  I'm not sure it is true.  Voltage divider will still be the same for all speakers - bass/midrange/tweeter  as long as speaker impedance stays about constant.   I'm not sure you can notice 0.9% loudness reduction (gauge 16), but if you can it will be for all speakers in the same percentage -  should not change the sound.  Also, the lowest impedance might be at different frequencies - even at 20kHz.  Uneven speaker impedance with resistance in series (thin wire) can affect (smear) the overall sound - not only the bass, but tube amps have output impedance of few ohms and nobody complains about the sound (or poor bass).