lighttpd works fine for me on a RPi 4 with Buster. There shouldn't be anything that was changed on a RPi 4 that would have affected it.
What happens if you run "sudo /usr/sbin/lighttpd -D -f /etc/lighttpd/lighttpd.conf"?
Nah. Cloudflare does handle www.raspberrypi.org which is why it has a different wildcard certificate issued by them but downloads.raspberrypi.org points to servers hosted by Mythic Beasts.
Because people are making 4K60 content? It isn't just gaming either. It isn't costing you anything extra to have the 4K60 support anyway so why do you seem so angry about this? If you don't need it then don't enable it.
Yeah. They're far more expensive anyway.