What a journey! And a lot of great description. I'm going on a similar journey now, but don't have your skill to describe the experience.
For speaker cable I'll suggest looking at Zu Audio and HiDiamond. Zu is not all too well known for their speaker cables but I doubt I'll ever part with mine - everything thing they touch becomes more clear and extended with improved soundstage. Close were the HiDiamond D8, just warmed things up slightly and that's not my preference. Zu is a US company so maybe not as easy to get for you, but HiDiamond is out of Italy.
For speaker cable I'll suggest looking at Zu Audio and HiDiamond. Zu is not all too well known for their speaker cables but I doubt I'll ever part with mine - everything thing they touch becomes more clear and extended with improved soundstage. Close were the HiDiamond D8, just warmed things up slightly and that's not my preference. Zu is a US company so maybe not as easy to get for you, but HiDiamond is out of Italy.