Upper right Pane

Open the Bookmarks Library on a folder which has at least 2 sub-folders.
In the upper-right pane, none of the folders has the little triangle that allows to open the folder.
One must double-click the folder to see the bookmarks inside.
Once inside a folder, there's no "...up one level" to go back.

The lack of ability to expand both folders (in the above example) is limiting the flow of work.

Details Pane

• Select a bookmark (in the upper-right pane) and expand the details pane to show the description field.
• Select a folder in the upper-right pane.
  ** The Details pane collapses automatically to hide the description field.
• Select a bookmark again
  ** The Details pane expands automatically to hide the description field.
• Select two lines in the upper-right pane.
  ** The Details pane collapses automatically to hide the description field.

This "auto behavior" disturbs the work because some bookmarks get covered suddenly.
It is also very distracting when the UI changes on its own.
When relevant, the content of the Details pane should be cleared, but the layout should not change.

All the above issues are new, and were introduced when the SeaMonkey original Bookmarks Manager was replaced by Firefox Bookmarks Library, in order to solve the data loss bug.

Side Note
The UI of the original Bookmarks Manager was "as expected", which was helpful to the user, when massive editing was being worked.

Bug 1378089 changed the ui. It was backported to the unofficial 2.53 so set this one as affected in case we ever do an official version including the backports.

Bug 1476662 should help with some of the folder isses. Planned for 2.53.2. Should be in tomorrows unofficial build.