Advice on DIY NAS plans

[Enquiries]

Hello! I was hoping you could review my high level DIY NAS plans and possibly offer advice or hardware suggestions. I'm looking to build something for file storage (photos, videos, documents, games, et), editing 4k Youtube/Twitch videos, and to host various services via Docker. My background is very technical. I'm a software engineer, I've been building my own computers since I was 10, and I'm pretty comfortable with k8s and docker.

My current plan is...
OS: TrueNAS Scale
Docker Pool: nvmes in raidz1
File Pool: Either SATA SSD's or HDD's in raidz1
Network: 10gbe (limited by cat6)
CPU: Threadripper or server CPU
GPU: Integrated or cheap
RAM: 64 GB
Backup: Backblaze

I'd like to start with less disks and leave room to expand over time and ensure I'm saturating the network connection.

Questions:
Does it make sense to have 2 pools?
Should I stick to 1 disk type?
Any CPU and mobo recommendations?
Should I start with more RAM?
10gbe switch and pcie card recommendations?

Thanks!