You are right... The first Pict. shows the belt is too short. The perfect fit makes the belt even with the top of the rear pulley (torque drive), and sitting snug around the shaft on the front pulley (variator).
Where are you located? Maybe someone here is local to you, and has a source for the Bando belt. There is a dealer here in florida that has been selling cheap Ebay belts for years, and I catch quite a few of them in repairing his work. Just cause the dealer sells it does not mean it is correct.
Maybe your dealer is right, and the dayco works but I do not know.
The CVT cover not only holds the starter gear in place but it is what keeps your bike from falling apart. The engine case is cast aluminum, and will break in half if you ride without the case cover. That is where the strength comes from.
You can take a magic marker, and sort of "paint" the insides of the front pulley. When you ride it will rub off the marker, and show you how far up the variator the belt is riding. It should go all the way up. Same as the rear when the bike is sitting.