Problem/answer.
Just spent over an hour with 3 different levels of tech. IF you connect wifi, delete the song/album/playlist that is having issues playing, then search/download it again (by the little cloud), and then you see it is "downloaded", click the three dots at the top. It will show a cloud again, and click the word "download". Now you should have the music again on your device, and you can go back to non-wifi to test playback.
This should fix the issue, but unfortunately, you will have to do that to every single affected song/cd/playlist individually. (or you can basically wipe out your icloud music library and start from scratch).
The real problem is not that, however. The real issue, and why some of my music was disappearing even from ripped/imported songs/cd's, is that in its infinite wisdom of cloudiness, Apple has decided to replace songs on your device with new, or what they consider 'better' versions. So if you have songs that are rare, impossible to replace, and having trouble keeping them from fading to gray and not playing, this is why. They will be replaced by "apple versions", like it or not. I've got 1/2 an iPod to illustrate this if anyone has doubt.
I was provided a link for feed back on this issue, and i will be providing feedback.
I do not think I will go through even attempting to do this on every single song/cd/playlist and have them just get replaced/disabled again.
I hope there will be enough noise about this setting of their choosing my music for me that it will be changed. It really is risky if you have precious music versions you like, because they will be replaced for you.
In the meantime of waiting for this to be fixed, I'm going to begin spreading out my downloading from Amazon music and hope they aren't as invasive about choices.