The smart-tool idea whereby zones around a note access different functions is fine with few notes, but as things progress you zoom out to get an overview, then manoevering over the right bits of note gets difficult. Result? I'm constantly zooming in and out.
 
I propose a key+mouse model.
 
That way I only need enough accuracy to actually hit the note with my mouse. Everything else is key and mouse movement.
 
Put the default key layout under the left hand (with options for the right side) - NOT function keys like now. I realize there are defaults already, notably the D key. Studio One uses the number keys, that could be an alternative.
 
Here to start the ball rolling is my suggestion:
 
A) *** Note Selection/Moving ***
 
1) Mouse click selects note.
2) Keep mouse pressed to move note
- Moved note really moves live to reveal any duped notes underneath
- Pressing Esc before mouse button release cancels move and the note jumps back.
( - Some unskilled in mouseclicking may accidentally move on select, so perhaps a Preference to add a key to move? But please no noticable time delay; that is poison to the practiced power-user)
 
B) *** Note Creation ***
 
3) Key A+mouse to Add new note of default duration and velocity, as set by user in Preferences.
4) Keep A and mouse pressed to set note duration
5) *Additionally* press V (Keys A and V together) to change velocity (with scale displayed, see below).
6) SAVE the note duration and velocity on mouse release (volatile - not on disk!)
7) Key Q+mouse to add a new note of SAVED duration and velocity (in effect, use previous note settings).
- If this is first note then use Preferences default duration and velocity, same as in Key A. Do NOT crash Sonar.
 
C) *** Note Editing ***
 
8) Key S+mouse to set Duration (S = "Stretch/Shrink?" Or D?),
9) Key V+mouse to set Velocity (display value and/or a little vertical scale near the note to assist human to visualize),
10)  Key E+mouse click to Erase a note - or: right mouse click
 
Much of what I suggested is how it works now. I'm just saying: don't change those. And I like Grid Enable/Disable on N, that's good.
Edit: Changed after giving this some thought.
 

I agree completely!!! It's as if whoever programmed Sonar's midi implementation never really USES it. If they did, they would see how clumsy and cumbersome it is!

I think you can reassign those function keys to more accessible key combinations - I'm not a big fan of using those either. 
 
However, I actually prefer the way it is now rather than having to use a different key for each operation.  For detailed start/end time adjustments I always zoom in anyway so I can better see the timeline, and for velocity I use a combination of notes and CC view, whichever works better for where I'm at. 
 
That said, adding some of these hot-zone features as optional keyins could be convenient...