My big tip is if you haven't already, switch to a local package repository. There are a lot of people mirroring the software packages for mint and you can switch to one that is geographically the closest to you for better speed and to spread out the server load.
I love Linux Mint and it's what I install on all my decom-laptops turned servers. It will do pretty much all you want to do in Windows and then some. The only thing it probably isn't the absolute best for is PC gaming but if you are just using a laptop it probably doesn't make much of a difference either way.
If you like Mint then I also suggest PopOS. They are both based on Ubuntu so a lot of the paths and the package manager are the same. The killer feature there is auto-tiling Windows which is like the window snap feature in windows but happens automatically. It's not for everyone but once I started using it, it changed my entire workflow.
Last thing is, if you haven't already, familiarize yourself with running docker containers. A lot of stuff that's complicated to set up is a breeze with docker and docker-compose.
I use Syncthing on all my endpoints Windows and Linux (can't speak for Mac) to sync to my TrueNAS server. It has a built in tool to just back up to backblaze on a certain schedule.
I know you can use Syncthing with unraid in Docker. I have it set up so sync all endpoints to my server and then the server pushes the latest changes back to all the endpoints. This is overly redundant and you don't have to do it that way but all endpoints and my server would have to die at the same time before I lost any data. It's sort of a backup scheme in and on itself.