I just played around with this and I think I've got a solution for you. I learned something in the process too, which is nice. I didn't know you could add a Playlist Group as a Pane in a view. That's pretty cool.
I'm going to assume you have a view set up that has a playlist group as one of the Panes, *and* that your playlist you are interested in is shown in that pane. If you don't have that, hopefully you can create it quickly.
Now, with your Pane with Playlists in it, go click on your playlist. You should now see all of your files in the details list below. The other Panes should show only what is in the playlist: Albums, Artists, etc. Go find an album or artist you want to remove. Scroll through the Albums pane or the Artists pane, or whatever. With those files showing below, click on the files in the album, highlighting them all.
Now look at the Playlists pane again. Notice that there is now a grayed out check mark next to the playlist? Click it. You'll get a box asking if you want to enable Panes Tagging. Say yes. Now the check mark should have disappeared, leaving an empty box. Those files are no longer in that playlist! You can click the box again to re-check it, and those files will be in the playlist again.
Using Panes tagging like this, you can add or subtract albums from your playlist very easily. Give it a try and let me know how it works for you.
Brian.