Leave Servarr as last thing to setup because it requires many services to work together and even small mistake in config will make it not work. Its not hard, but it will be easier after you learn how to setup jellyfin or audiobookshelf.
I have no experience with your hardware, but after you install docker and docker-compose get Portainer and get familiar with docker compose. Portainer is simple gui that lets you manage all containers.
So for example, you get docker-compose example for jellyfin, eddit PUID, GUID, path to your library folder, copy that in Portainer Stacks, hit deploy and BAM! Your jellyfin is available on localhost:8096
You might face many issues in the begining, but dont give up, its getting more and more easy over time. I still think Im a noob, but have no problems with my 40ish containers running on poor home server 😉. Dont forget this community is awesome and helpfull
I use jellyseer to grab movies and shows, there is also overseer for plex. I dont think you can run that in kodi, but looks like better approch to me anyway. There might be more options that Im not aware of
Backblaze B2 is 6$ a month for 1TB and first 10GB is free. You pay proportionally (it cost me 2-3$ for last 7-8 months for 20-150 GB that accumulated over time). Keep in mind that you will spend more if you download backup, but you should use cloud backup as last resort anyway. I backup to 2nd local disk and also to B2 daily with Kopia. Didnt need backup fortunately, downloading from B2 small files ocasionally just for testing setup
Its not just cheaper, I love it because I dont have to deal with Gshit company
My TV is not even smart. I use 40$ xiaomi tv stick (android 1080p). Its powered from USB port on tv and connects via wifi. Its not the fastest device, but it works just fine Edit: not sure about price anymore, seems like its more like 50$ now, but still cheap IMO