You're missing one thing: drawing a dependency which is currently the default 
behavior 
for "left click and drag". 

Oh yes you're right, I forgot about this. Stupid since, this was the reason for 
this 
proposal, I keep on starting to draw new dependencies when I would like to move 
a task.

So personally, I'd like to have this under the CTRL key, since it is something 
one is 
used less frequently (and more 'special') than moving tasks.

The behavior is in fact configurable through the properties file: 
http://code.google.com/p/ganttproject/source/browse/ganttproject/data/resources/
keyboard.properties
Some simple UI for editing this file would be nice, of course.

Let me add that changing this file doesn't change anything (at least not in 
Windows, Praha Beta 1 Build 255).

This issue is quite old, is it still valid at all? The problem using GP without 
a mouse (e.g. on a touchpad) or with a mouse without a good middle button is 
rather serious I think.

The issue is still open (as shown by the status field). As it is typed as a 
discussion, we are not sure what to do, or whether we need to spend time on it.

So, if you have a (new/good) proposal on this, please let us know and we might 
be able to make a decision what to do :)

On the middle mouse button: what should happen when using it? I do not know 
about it... :/ (scrolling is for zooming, but that can be done using shortkeys 
or clicking the toolbar as well)

I think you need to open a new issue about the broken keyboard.properties file, 
as it is (somewhat) unrelated to this discussion.

Thanks for pointing this out - every team uses his bugtracker differently, 
sorry for using the wrong posting methods at first.

Mouse handling of timeline bars: Issue 270
keyboard.properties does not change assignments: Issue 271