Mouldybanana

Nice chart. I do feel like amd is missing a bit from this chart as in general they sell for less than nvidia on the used market.

I would go with the proposed picture, but I wouldn't plug the router into the server. Let your router route, and let your server serve . Running Windows Server in a VM would do fine. dnsmasq is super fine if you don't mind text files, but if you want a GUI and already plan on doing Windows Server run DHCP and DNS on there. Its trivial and doesn't take up very many resources, and if shit goes haywire you can let your router do DHCP and DNS.
 
The access points are always a good idea.
I would also agree with upgrading to a PoE switch for your cameras and AP's, just to save some space. They aren't too expensive, and its nice having less wires . 
 
Really, its kind of silly to roll your own DNS. Its possible, but rather pointless. 

Although I like the idea of giving 1 physical system the responsibility of what would traditionally be multiple systems I wouldn't recommend putting the DHCP router inside a virtual machine on a file server. If UnRaid misbehaves and the router VM stops functioning you'll have a hell of a time recovering it if you don't have IPMI on a separate network interface. DNS i think is fine though I've never used it myself (my own DNS server) so I could be wrong.
 
Also if the file server handles all the network traffic you'll lose file transfer performance when the network is being heavily utilized.
 
For wider WiFi coverage definitely use access points and not routers with access points built in unless you want to make your wireless network separate from your home network.

As stated above, you really don't want to have your storage server in between your network and the cloud.  Nor do you want it to handle the DHCP functions.  If you have to take your server down for any reason, even for a hardware upgrade, you kill your whole network.  

Why not turn the UnRaid server into a router itself? https://arstechnica.com/gadgets/2016/04/the-ars-guide-to-building-a-linux-router-from-scratch/
 
Though if it were me, I wouldn't have my file server be involved with handling network data.

PUtting your router on a vm does make it a pain if something goes wrong or you want to ugrade the server, just saying.
 
1. Id just install pfsense or untange. Boom easy os that has dns,nat, caching, dhcp and all you need
2. Win server runs just fine in a vm.
3. Poe (or poe switch)injectorfs for the aps and camera
4.Id personally swtich from unraid to anouther os like proxmox or just plain kvm. You get more control with networking and storage.