Some of your suggestions were implemented in Solarus 1.2 that was released a few days ago:
- When changing the id of an item in the left selector pane, the current id could be the default in the dialog.
Done in 1.2.
- Holding "control" and using the mouse wheel could zoom the view.
Done in 1.2.
- Making some tweaks to make the editor more friendly to smaller resolutions would be helpful - I have a machine running at 1024x768 and there are times when I can't see everything in a dialog box. One example is the new "destructible" dialog - would it be possible to lay things out differently so the dialog isn't so big?
Done in 1.2. The dialog of destructibles now has a vertical scrollbar if needed.
The "X" button on tabs is not done yet, neither is the "play music" button. These improvements are planned for Solarus 1.3.