I agree withm your and others points on finance. However, on spreading the game too thinly if such a lower tier tournament came to pass, that is why I suggested in my OP that the games be played as double headers with the senior World Cup game as the other fixture. The grounds and crowds would already be in place for the main game and the lower tier game would be just added to that original fixture.
The RLIF needs to be an autonomous body with jurisidction over international rugby league and should received funding from the WC and 4 nations with the big three getting a cut of the profits as suggested. It would take a decision from the big three for the greater good for this to happen and I agree there is not the will to do that, especially from the Aussies. The RLIF should also be in charge of rules changes. The Aussies changing the game as they see fit without input from anybody else needs to stop. The rules should be unified worldwide and the RLIF should be the people to administer this after due input from all parties.
The problem with double-headers is that the RLWC is being played in the latter part of October and throughout all of November. The pitches might not stand up to two games - I'm certain Man Utd wouldn't be happy with two games at Old Trafford on a single afternoon.
In an ideal world the RLIF would be a powerful and independent body, but it is currently in the hands of its paymasters.