2. Consider https://beets.io for management, it may be just the system you want. One of its features is converting you library into a lossy version while keeping your high res files in a very managed way.
As you seem knowledgeable, it looks like beets manages music you've already ripped, do you have a suggestion for ripping? Last time I tried, it was a disaster (I got a lot of poor quality audio and ended up nuking everything because it was too much work to listen to everything and try again)
It's been a while since I ripped my last CD, but I always found https://github.com/bleskodev/rubyripper very useful. It uses cdparanoia to get multiple rips and combines them into what it thinks is the exact information located on the original cd.
These days, I can fortunately download most stuff directly from bandcamp :)
2. Consider https://beets.io for management, it may be just the system you want. One of its features is converting you library into a lossy version while keeping your high res files in a very managed way.