Couldn’t you just get a spotify account?
Why?
Again, why?
If the OP is like me, he has a shitload of music in CD format, and much of that ripped onto a HDD.
The bit causing the problem seems to be the interface between the NAS with the music on, and the amp.
In my case, my Mac Mini is connected directly to my old Yamaha A/V amp via optical TOSLINK, and I control choice of playback via Remote on my pad or phone.
It’s the lack of a direct optical link that seems to be the main problem, requiring the Pi, but as someone has suggested, keeping the Pi powered up continually could solve the issue with the cards failing.
Worth doing that, and seeing if the issue goes away, thus making a cheap solution.
To return to the first two questions, I refuse to have anything to do with streaming services until they pay artists the true value of the content that they stream. A million streams would pay an artist $900, or thereabouts, if those were downloads from iTunes the artist would earn $900,000,
When I download a track the artist gets a proper royalty, and when I buy a CD, especially at a gig, the artist gets full payment for it, and in return I get a physical object that is a backup if the file gets corrupted, and has been signed by the artist as well.