Playlist issues multiplying

I still am trying to figure how the logical addition of "Delete Song from Playlist," hasn't been added to the dropdown menu when selecting a particular song one wants to eliminate from their playlist. This hardly seems to be a new issue, from the comments I've read on this issue for a while now.

What I think would be incredibly helpful would be a short YouTube video to show how it's done on an iPhone, a Mac, and Windows setup, step by step, because I've tried to replicate the steps as described in text, and come up completely empty each time. 

But I digress.

The last couple of Bluesound software updates have created new issues regarding playlists and the Bluesound for me, with a couple issues that were clearly prevalent for a number of months, and continue to be an issue, especially on the desktop version for a Mac. I'm running OS 10.11.6. In the first few updates after getting the Bluesound, I could load the playlist and hit a certain song down the list almost immediately, as the thumbnail images for each album cover loaded very quickly in the list.

That's not the case anymore.

Now, after loading my playlist, the 8-10 or so songs that appear in the list without scrolling have a circle and music note as the thumbnail for a couple of minutes, and I can't do anything with Bluesound until the album thumbnails load for those appearing in the list. Very frustrating.

If that was the only issue.

Today, I learned upon scrolling through my list in the playlist, that I guess you can have the same song listed TWICE in the playlist. You would think the playlist would refuse duplicate songs from the same album in the same list. 

And the most recent frustration, is that I also noticed something very annoying. I have a single playlist that was largely created a year ago, and I've been doing the same thing over the past year for any new music I purchase, to add a song to the playlist using the pulldown menu, and "Add to Playlist," and select that playlist. But I began to wonder why I haven't seen any of that "new" music appearing in the list. Upon scrolling through the full list (through the artists that begin with the letter "A," none of those albums added in the past few months appear in my single playlist. 

My Bluesound library is about 600 CDs, and have a single playlist of about 1,600 songs. The size of the playlist wasn't an issue probably about six months ago, as it loaded quickly, before the album thumbnail issue arose, and I've kept hoping that the latest software update would rectify that issue, to no avail.

I know my issues amount to more than a single issue here, but any help on what amount to four issues (trouble with deleting a song from a playlist, slow access to the playlist to play, duplicate songs in the playlist, and songs failing to be added to the playlist) would be greatly appreciated.