Keyboard Shortcuts Like Paste Special Not Working

For the paste issue, it sounds like the dialog box might be opening offscreen. Look for LastX and LastY values in a registry path like the following, and change them to 0:
 
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR Studio\<version>\<paste dialog name>
 
For the silent hardware synth issue, you'll need to trace the whole path:
 
- MIDI events on expected channel and in the pitch range of the patch with durations long enough to get through the attack portion.
- Forced MIDI Out channel in the track header is correct if used.
- MIDI track Output port is correct.
- MIDI meter in the track is active during playback.
- If available, the MIDI activity indicator on the Korg is showing input.
- Korg's receive channel matches MIDI events or forced output channel in SONAR.
- Master Volume is up.
- You can hear a repsonse from the Korg headphone out.
- Audio track in SONAR is set to receive input from the correct interface channel, and has echo enabled
- etc. etc.
 
Quantize will just snap the existing note ends to the nearest grid line for the specified resolution. To set a specific duration, use the Event Inspector module in the Control Bar or Process > Find/Change.

If you check 'Note Durations' it quantizes note ends/offs as well as note starts/ons. But calling it 'Durations' is somewhat misleading because if you quantize  'Durations' without quantizing starts, the durations won't be quantized - only the note ends.

To brundlefly,
 
Your answers solved most of my problems.  I cannot imagine how I would ever know to edit the registry but, indeed, that's what fixed the keyboard shortcut problem.  The MIDI playback is mostly solved but there is still something not quite right in the settings on a new USB audio interface that I bought (a FocusRite Scarlett 6i6).  I'm waiting for their technical support to respond to an email.
Thank you for your very spot-on assistance!
 
UCG Musician