Yep, provided you're running Catalina or a later version. With a USB-C hub, you should™ be able to plug all your six displays into one card... and USB 3.x devices.
Same here. My first build was in September 1999 (I still have the receipts for the stuff I bought, which is how I remember after all those years) and used a 400 MHz AMD K6-2. Little did I know the lack of on-chip L2 cache was detrimental to performance.
Same here. In the laptop universe, Intel's CPUs were more power-efficient (excluding the not-so-mobile Pentium 4). The [ultra] low voltage Pentium III and Pentium M were excellent, AMD's CPUs simply used much more power.
I still remember the GHz race in 2000. When I did my second build in July 2001, I went with a Duron rather than an Athlon though as it was significantly cheaper, and I was kinda put off by the horror stories of 1 GHz Athlons blowing up within seconds if the cooler wasn't mounted 100% right...