Sounds pretty pricey, but it’s hard to say without being there.

Not without alot of messing around, I’d just stick with 2.5.

You can go down to literally a usb stick or even micros card if they support it. Esxi works on an SD card with a few config tweaks.

Nas software is more friendly and just works. Windows doesn’t have a great raid option, but nas do. Windows desktop also has alot of artificial limits and is less stable and will reboot for patches at inconvenient times.

I simplest terms, it’s like use a flat screw driver on a Philips head. It’ll technically work, but there are just plain better options that will work better and easier.

Ah okay, I’d recommend softether as an option as it doesn’t technically NAT changes to put into place. (easier if you can, but can work without it)

1. Router type literally doesn’t matter.
2. Windows server can absolutely get dhcp address
3. You can’t remote into Nas hardware as they don’t have a desktop
4. Play a bit more and explore these technologies in your own home first, or. You’ll have a huge headache waiting to happen.

Skip the pi’s

Grab a refurb mini pc off of amazon and max out the ram, and install proxmox. Should have a nice little sandbox for under 150.

The first question to ask is why? Exchange on prem is nothing but a pending security breech. Especially at a small business without dedicated experts and resources. You’re realistically not going to save money either with how cheap hosted email is in comparison to a virtualization stack underlying storage, and monthly management time. You’ll also have less uptime than Microsoft.

Coming from someone who was managing exchange on prem 6 months ago until I left that train wreck of an environment.

They’re paid to get It working, not make it pretty. Most of those guys don’t make any real money after expenses. The more they do, they more they earn.

Proxmox is the best option here

Just use zfs within proxmox, only reason you’d do disk passthrough to vm would be if you’re using esxi and want to use zfs still.

No, everyone needs a Colo datacenter’s worth of hardware in their moist basement