I'm pretty sure that it's meant as a second layer of defense, so it should work out. After all still not recommended as Bitdefender really offers enough protection and the only effect you might see is that your PC won't be running as smooth as before when adding Roguekiller to your config. I personally think that those setups with a 2nd layer of defense like Malwarebytes or HitmanPro.Alert are unnecessary for the most part and are only worth considering when not using a full security suite (For example Panda Free, Bitdefender Free or Immunet.) As you are using the flagship version of Bitdefender (Bitdefender Total Security) you shouldn't worry about not having enough protection