Thanks for your support, guys! 
I really hope I will get this work properly. Good news is now I've got the full functional structure of the editor in my head. 


Well, soon I've got key bindings and all preferences working. What's next? New audio engine, track view, console view, staff view with notation? ROTFLMAO...

Key Bindings Editor looks like this just now. I'm a bit stuck with it but I try to solve the major logistical problems later this week. 
As you can see, the major difference in design compared to the built-in SONAR Bindings editor is that my version binds Functions to Keys, not Keys to Functions. I'm sure this is more intuitive approach for anyone! I may be wrong but that's why I will include 'Find by Key' and 'Find By Note' buttons, too. 

My logistical problems are related to the way how I keep bindings in memory and how to make wanted function foundable as easy as possible.  Last problem is related to the huge amount of functions to bind.  I have to collect them manually one by one....