Father Skywalker said:
they would've at least had plans and mention of it during episode 6. Darth Vader never told luke skywalker that "join me and together we can destroy the planets with the death star as father and son"".
The hell are you on about!?!? The Death Star from the beginning was a weapon of fear to keep the systems in line so they could just dissolve the senate. It wasn't created to destroy a list of planets. They only needed to demonstrate it's destructive power once to test it then the second time to destroy the rebel base. After that they would have all the fear they needed to keep their power and they would set out to rule the planets from that fear.
