Gentleman,
Downshifting and releasing the clutch through every gear at every stop is not recommended on a bike that has the swept area the size of the Valkyrie. Your brakes are more than adequate to stop your bike. In doing so in wet conditions or in a curve can easily dump the bike because you have caused the rear wheel to lock up - BOOM - DOWN you go.
However, those that make it a habit of using the "engine brake" as well as the lever/pedal brakes are robbing themselves of thousands of miles of tread life on their rear tire. It's foolish and expensive to "engine brake" when it's not necessary.
And, tho I have read some who say that this will not cause wear on the drive train, it will cause wear on the drive train starting at the clutch and moving all the way to the final drive.
When slowing, one should downshift into the gear commensurate with current speed in case of the need to power out of trouble. If you are only stopping at a light or stop sign, keep the clutch disengaged (pulled). You'll save yourself time and money on your rear tire and reduce the strain on your drive train.
Read about tire wear on motorcycles here