There is little performance overhead from running a VM. However there’s a substantial administrative overhead for keeping a virtualization system running just for home assistant.

If this a hobby to you, sure, you do you. Time you enjoyed wasting is not wasted. But it’s way less effort to just run everything you need in a container stack - especially if are you already running containers for other things.

Yeah, just set them up in another container.

Addons are just software.

I only run mosquitto right now, but it’s not exactly hard or complicated or time consuming to set up.

There is no compelling reason to run home assistant in a vm instead of in a container.

I’d get rid of the virtualization layer in your specific case and save yourself a lot of hassle, especially on smaller systems.