Personally, I’d expect it to be fine. There’s not a lot of CPU usage for those apps. The only part I see it potentially struggling is the file transfer (WiFi on the Zero W or Ethernet-over-USB).
Might be better to get a Pi 3b with Ethernet on board
Either word of mouth or browsing the recently added section on my Plex share
There’s a discord server that has a bunch of IPTV resellers. PM me if you want a link
Generally, these are referral only and for people you know IRL, not just online. I’ve never seen any discussion of them
Is Orange not available? We use them on the mainland and they’re decent