thanks for your question.

This is indeed a valid approach but won't work until in RC2. The 
current approach to the keystroke actor is that the emulated 
keypresses press and release events match the press and release 
events of your the respective button on your remote. In RC2, you can 
modify this behaviour.

Apart from that, what you want to do can be accomplished with an 
AppleScript very easily and reliably:

tell application "DVD Player" to quit 
tell application "DVDPedia" to activate

If you close the "DVD Player" window, it closes the entire 
application, thus I placed "quit" here.

The other solution (and just as reliable) would be to just send an 
Apple + H to DVD Player as Apple + W (the Apple + Shift + W combo you 
mention doesn't seem to be valid btw) would have the same effect as 
Apple + Q in DVD Player. And then, in an AppleScript actor, use the 
second line of the above script.

Hope that helps.

Best regards, 
Felix