Flatpaks are pretty great for getting the latest software without having to have a cutting edge rolling release distro or installing special repos and making sure stuff doesn’t break down the line.
I use Flatpaks for my software that I need the latest and greatest version of, and my distros native package for CLI apps and older software that I don’t care about being super up to date.
My updater script handles all of it in one action anyways, so no biggie on that either.
Flatpaks are the best all-in-one solution when compared to Appimages or Snaps imo.
Favorite heavyweight Type 1 hypervisor: XCP-ng. It’s open source, runs on a ton of enterprise and consumer-grade hardware, has always been rock stable for me, even when forgetting to update it for like 6 months, still ran everything like a champ.
I need to try ProxMox, has some cool features. XCP-ng is pretty intuitive though, UI makes sense and is cleaner than Proxmox. The integration in Proxmox with the Incus project is pretty cool though, especially being able to run VMs and containers and manage them together. I’ve been thinking of trying that and seeing how it goes.
For containers, I just install Debian and run Docker on there. Stable, simple, nothing fancy. If I need something more up to date, I typically use Ubuntu Server.