I've had a lot of success with a QOTOM box from aliexpress.
They're little fanless boxes running basic intel Core chips, in a variety of configs.
I've run OPNSense and PFSense as routers (also doing wireguard, torrents, etc), as well as just standard Ubuntu server.
Very small and low power, and pretty cheap. They come in a variety of configs.
Moving to Caseta for lighting from the random mix of bulbs which never quite work was amazing. It's also much cheaper to put in one controllable switch than replace the 6 bulbs in the light fittings connected to the wall switch. Those bulbs always fail in weird and non-debuggable ways.
I use Crafty Controller (https://craftycontrol.com/) to manage the minecraft servers. It runs in a docker instance and gives you a nice web UI to manage each minecraft server. I use it to delegate control to my kids to create and manage servers as necessary.
Finally, if you're not using a config mgmt tool, I'd start looking, so you can make everything easily re-doable. Personally I'm using Ansible, but puppet, chef, salt, etc all work too. Ansible is easiest given it does need it's own infra. I like it so if something dies I can redeploy everything onto a different server.