So I love Sonar, of course.  Just trying to cut down on aggravations that didn't exist in previous incarnations of the product, historically called Cakewalk.  So when you accidentally hit some random keyboard key and you don't know what you're looking at anymore, what are you suppose to do?
:-)

Cakewalk has always used single key bindings. The bindings in SONAR have changed over time so either learn the new ones, rebind them to the old function where possible or bind them to do nothing. Then there is the undo function.
 
If this post is about an X series version of SONAR, it is in the wrong forum. This forum is for older pre-X series versions of SONAR.

Are you referring to the panic button ("the Scream")? Does it not exist anymore (I'm not at my DAW)?
I don't know what's the equivalent to it (if it's gone).

There is only one keystroke you need to remember: CTL-Z. That still works in X3, doesn't it?