Rough Diagram of WIP: https://i.imgur.com/u3vgUAF.png

I have a small lab setup that I've been working on but I'm a little stumped on how to achieve what I want. I have a machine running Proxmox that I use primarily for running VMs for work training and hosting a Linux Game Server VM. My primary goal is to be able to access my Proxmox host when I'm out of my house, because as much as I love my super silent M1 Macbook, I've hit some snags when I try to use some VMs locally. Secondary goal is to break up my home network some, as everything currently lives in the same space and feels icky, especially with the external game servers.

I originally just set up an VM running opnsense and configured OpenVPN with MFA, but I decided I didn't want to use a VM if I was potentially going to actually use it as a firewall since I don't want homelab stuff bringing down the whole home internet while my wife is watching a show or something. So I picked up a Lenovo m720q for cheap with 16gb of memory and a 256gb NVME, tossed in a quad ethernet nic, and loaded Opnsense on it. Right now my ISP router is set for IP passthrough and handing the public IP to my Asus router, but I'm thinking maybe I should flip this and have the firewall take over the role and just let the Asus just handle wifi.

My networking is rusty at best, and I'm really stumped on the right way to handle some of it, like isolating the game server VM from other VMs and most of the home network. Hopefully the network diagram is easy enough to read, but what should I be doing differently?