Some NICE ideas here. I have another point of failure that I have never heard discussed. That being your IP (Internet Provider) I have been in a 10 year long battle with mine (they have a monopoly here) and recently tried a 5g Internet option. IT also failed miserably. I do believe that the 5G idea a good one to pursue but it is still in its infancy and not really ready for primetime.
You can't just do an online speed test and expect an arbitrary one shot test to give you ANY real idea of thruput from your IP. It only takes a lost bit here and there to totally corrupt you listening pleasure. Just because you Speed test shows you have some outrageously high numbers doesn't mean you can consistently stream flawless audio or video. It doesn't even take an A/B test to notice a complete dropout of the internet connection.
One way to see how fault tolerant your system and IP is, is by looking in you modem for it's 'Fault report' page. That is assuming you have a modem of a quality that shows such information. I personally am using a Netgear right now and it has great fault reporting down to the second.
You should really start at the Actual 'Start' of your streaming system and in any environment , on your side of the wall socket, that is the IP.