The following are three feature requests for the unscheduled drafts column.
1) Adjustable column width
The unscheduled draft column, (#draftsdrawer_cont) is currently set at 13% width. Rather than debating what the optimal width is for convenience and visibility, could this width instead be user defined? A feature such as dragging the cursor on the left of the column to widen or narrow the column would work nicely. Since the calendar is fluid, it would adapt accordingly.
2) Sticky drafts
I've found myself having to prefix the title of my unscheduled drafts with "A1" to achieve a "sticky" effect whereby the prefixed drafts remain on top of the queue. I understand that this pushes you into the realm of writing unique plugin specific data to the back-end database but as this plugin becomes more feature reach, perhaps it's inevitable that you'll follow this course. Either way, it would be a useful feature.
If you're absolutely against creating unique data tables for this plugin, you can still implement the proposed feature using two different methods.
Method a) Bear in mind that WordPress by default has a "Make this post sticky" check box for each post whether it's a draft or published. You could simply extend the plugin to detect what drafts are defined as sticky and reflect it accordingly in the unscheduled draft column. The only downside to this is that users will have to remember to "unsticky" the post at point of publishing or scheduling. This could of course be automated with a simple modal dialog box asking the author if they'd like to publish/schedule as sticky or unsticky.
Method b) This second method is much cleaner and requires far less code because it's leveraged by existing default WordPress functionality. I'm referring to the use of custom fields (see codex here). For each post that the user wishes to reflect as sticky in the plugin's unscheduled drafts column, they'd simply need to add a custom field.
Meta-data custom key:
Meta-data custom value(s):
* sud = an acronym for "sticky unscheduled draft".
The plugin in turn would interpret the meta-data and reflect it as sticky in the unscheduled column. The benefit to this method (b), unlike method a, is that a sticky feature exists exclusively for the purpose of the plugin without confusing it with the standard WordPress sticky feature.
If you really want to achieve a point of perfection with this feature, you could go one step further with method b by automating it. This simply entails adding a custom meta-box to the to the post editor page (see codex here). The meta-box would consist of a mere check-box to opt into the plugin specific sticky feature.
EDIT: It probably makes more sense to add this to the calender's unscheduled draft column. I'm referring to the links that drop down beneath each draft i.e.
Edit | Quick Edit | Delete | Sticky in queue. The link could simply read "sticky" but this could lead to confusion with the default "Make this post sticky" functionality.
Under the hood, it's achieving the exact same thing as the standard steps for adding custom fields and values to posts. The benefit is that it involves six or seven keystrokes less. The benefit for you, the plugin author, is that you can implement this useful feature without having to create custom plugin specific database tables. As you've explained to me before, whether the plugin is installed or uninstalled, all data is independently stored. The implementing of method b would continue this principle.
It would be useful to able to toggle between "order alphabetically" and "order by date added".