Helix for a better default config. But you’ve probably already set up vim the way you like it.

Cloudflare supports NS records, which is what you’re looking for. Except it probably only lets you create a zone for the top level domain, so you can only delegate to other providers. AWS Route53 will let you create subdomain zones, and will let you create NS records to set up delegation.

How’s it look with Jellyfin?