So yes, your diagram does make sense. As others mentioned, VLANs depends on how many rules you want to program. Personally, I have home automation on it's own VLAN anyways, just for security.

You mention "reliable" here.... Where, the switch fails, then what? My home setup, off the router, I have 2 switches, and my NVR connected to it. One switch is hardwired network. The other is just the wireless access points. For redundantcy, I designed my network this way, so I can work on the hard wired, and wireless works. Or she complains the wireless network isn't working, I can just reboot the switch remotely, and not affect her hardwired work laptop, or hardwired apple TV she might be watching.

To further redundantcy, I have a Wattbox, which reboots the modem if we loose internet, as well as I have it scheduled to reboot the modem once a week for redundantcy sake. The switches are on this, so I can reboot them as well. I'm lazy, and I don't want to go downstairs to reboot this stuff LOL. Ubiquiti has similar power management products.

Really designing a network though, think, "what do I have to do, if this fails?" as well as "is there anything I can do to minimize network downtime?". Little things make a huge difference in how you manage your network. The less time you have to spend fixing, or troubleshooting it? The more time you can enjoy the little things, like having the issue resolved already, instead of having to get the call of "the internet isn't working"