You don't need a Deathstar to bomb a planet into oblivion. If you got enough capital ships you can always to it conventially. Sure, the planet is not gone, but is not habitable anymore either. "Base Delta Zero was the code order for a naval bombardment to completely destroy a world's life, industry, and natural resources. This was carried out by melting the crust of a planet to a depth of several kilometers, enough to even wipe out deep-planet survival shelters and bunkers. Unlike other Imperial military codes, Base Delta Zero was not subject to change, so that there was never any confusion when it was issued." From Wookiepedia (http://starwars.wikicities.com/wiki/Base_Delta_Zero)