I run Ubiquity AP (used to be flashed to OpenWRT but now stock) as well as Mikrotik, all local. Firewall is opnsense. NAS is FreeNAS, but not really use it at the moment. zfs is great. If you really need 48 port L3 switches, look into whitebox. I use used enterprise gear for lab, too much noise and power draw and no real use for terabit L3 at home.

Use opnsense instead.

It appears dumb, until you think of automated deployment and maintainance, leveraging existing infrastructure.

You can install Proxmox on top of Debian. I always do that.

My GrapheneOS phone is in airplane mode with cellular disabled and WiFi on.