If you use a horizontal 2-pane layout, you can have a playlist viewer at the bottom panel and an "Item Properties" (component) showing at the top panel.Whatever item you click on in the playlist viewer at bottom immediately synchronizes with the "Item Properties" panel at top.All the Metadata entries in "Item Properties" panel are inline editable.
Thread is in 3rd party so Derty is assuming you are using Columns interface. Items properties panel is a part of CUI. You're Selection Properties is an element of the DUI. So you are talking past each other.Your Selection properties is not editable as you have already figured out.