With a large part of the Death Star II still to build, with large portions exposed, I can´t see why making a ship clash on it to open a hole to fly through, that would be the worst place to find relatively safe route to the core... :)
And Lando sacrificing himself (and the rest of the crew and the Falcon)... If proton torpedoes, concussion missiles or whatever warheads they have couldn´t destroy the power generator, I can´t see kamikazing the Falcon doing any better unless yuo don´t mind deus ex machina solutions... :P