Key Binding options

Just wondering:
 
1.  why is there a key binding for "Insert|Stereo Bus" but not for "Insert|Soft Syth"????
 
Any way of making one anyway?  
 
2.  Ivory American Grand doesn't appear to object to overlapping notes.  I remember the days when overlapping notes would make a piano sample "burp", for want of a better word.
 
Has that issue been fixed somehow?   Or have my ears stopped working?
 
JG