iCloud Music, iPhone stored music...

iPhone 8, iOS 11.2.6...

Okay, so I know that others are trying to sort this out too, and I've read those posts. But not all of them seem to run through the same list of points. So if I can, I'd like to consolidate this into one question...

1) I have purchased songs on my Macbook, in the iTunes Library. They are locally stored.

2) On the same Macbook, I am signed in to Apple Music and have downloaded/created Apple Music plalists.

3) My music is also backed up to iCloud Music Library.

4) I would like to sync and store music files to my iPhone. And have done that.

5) I would also like to use the same iPhone to stream and download Apple Music selections/playlists.

6) To do #5, I need to have iCloud Music Library turned on. However, it will not enable ("temporarily disabled").

Now, as I'm beginning to understand it, if I have iCloud Music Library off... I can still sync music manually from iTunes on the Macbook to my iPhone, as long as it is NOT an Apple Music download.

I can also, with iCloud Music Library off, search for and play Apple Music selections. But I cannot download them to my iPhone.

To download Apple Music songs to the iPhone, I must turn on iCloud Music Library... at which point, I'll be asked if I want to "Keep Music" or "Delete and Replace Music" on the phone.

Is all this correct so far?

Now, here's the thing...

I have, at the advice of an Apple Advisor, just turned off iCloud Music Library on the phone. This allowed me to manually sync music from iTunes on the Macbook again. Over 6,000 songs (not my full library).

It also gave me error messages that said I cannot copy over any Apple Music songs. Okay. And on the phone, it also says that if I want to download Apple Music songs, I need to turn iCloud Music Library on again.

But then...

When I try to turn iCloud Music Library back on, I'm given the choice... either "Keep Music" that's stored locally (which I'd like to do) or "Delete and Replace" the music (which I'd rather not do, if it means streaming or redownloading all music again).

When I choose "Keep Music"... I get a message a few minutes later that says "iCloud Music cannot be enabled" and "Your iCloud Music Library is temporarily unavailable, please try again later."

I suspect that if I chose "Delete and Replace" instead, it will work... the iCloud Music Library will be enabled... however, then I'll be back to the situation where most of my music needs to be individually downloaded again so it can be locally stored. And in that case, only the music that's in the cloud.

Is any of this making sense?

So many hoops to jump through, I'm not sure what I'm doing here or where I'm doing it wrong.

In the end, here's what I'd like to do and I suspect others would like to do the same:

I would like to have local music stored on my phone, so I can play it without streaming or using battery life when I'm on the road, running, driving, etc. But I would also like to be able to log onto Apple Music (which I can already) and add those songs/albums to my playlists on the phone, even download them, if it's something I like.

Is there a way to have both? Permanetly stored local music + Apple Music playlists and downloads on the same phone, at the same time?