Currently you can move a clip freely to left or right unless it's locked in time.
That's OK.
 
I saw Danny Danzi mentioning in the "I must be a caveman" thread that when he moved clips to another track, he tried to be very careful to keep it in sync. He did not know that holding shift key down locks clip time during drag.
 
I move and copy clips to other tracks all the time. 90% of actions are done with the shift key. I suggest that when shift key is not pushed, clip can be moved to left or right only in it's parent track (or track lane). When moving up or down, clip time should be locked.
 
Behavior should be turned off by default.
 
If this sounds too complicated, I would like to see Adobe Premiere style clip moving system.

Sry, nope ;) The default behaviour should be no lock, no
matter where you drag the clip, like it is right now.

I'd definitely like this to be the default - I think it should be a user-controllable option though for people who don't want it.

Yes, only if user configurable ...

Naturally it would be user configurable and key bindable.
 
 
 

Voted.   I'd like a preference that makes the Shift key unnecessary for maintaining vertical/horizontal alignment.   Or... perhaps a preference that simply reverses the current behavior and allows free movement only when Shift is held.  Personally, I probably use the Shift key 80-90% of the time, whether copying/moving clips between tracks (vertical alignment) or moving envelope modes (horizontal alignment).