dscottj - I think your approach to everything is in keeping with my ways of thinking; "bulletproof."
Sorry for the confusion - I have not really set up any network. I want to plan it out with the proper equipment selections first, to avoid wasting time, and more importantly, money (from buying the wrong things).
Well, I do have a wireless router, and at this point in time my wife and I use it solely for our tablets (so I guess I really do have a network -- a very basic network). I have it connected via Ethernet cable to my internet modem, and then, in turn, connected to my PC. So, my computer remains hardwired to the internet. This is the current extent of my network. (I have a Roku unit that I was using with it, but I haven't subscribed to Netflix or Amazon Prime to make use of it. The 30-day free Netflix trial was OK, but I decided to postpone subscribing to any service like that for the time being.)
gtgray - I did not know that this was possible, accessing an external HDD and managing song lists without a CPU on the data source end.
I, too, try to do a lot of research before making decisions, and unfortunately my heavily researched decision to buy a TRENDnet TEW-812DRU AC1750 was flawed. While this router seems to work OK now (doesn't seem to have great range), I can see that it may not be the best, most well-advanced. Within a year of my purchase (about 1.5 years ago?), TRENDnet discontinued this model. I'm looking at the specs/features right now, and it says, "Share USB peripheral devices over the network including; flash drives, external hard drives and printers" -- There's no mention of any special feature that would make this unit particularly stand out in that regard. So, I doubt that my router is capable of computer-less sharing of data like the new Netgear ones. I must admit, that although my wireless router needs are minimal at this moment, my TRENDnet is working flawlessly for me, 24/7.
You never know just how good your router is until you set it up and start using it. After my experience setting up my router and Roku (not great signal strength) I decided that the Ethernet/AC module connections would be superior. There seems to be no sense in going wireless with stationary entertainment equipment -- you have to electrically plug this stuff in anyway; might as well plug in the data connection in, too.
I'm going to do some more overall network research, and then start a new thread with my tentative selected components, and solicit feedback; will include diagrams. Should be fun.