Abuses Landorus's Speed? Base 101 for a CB Set is not good at all. You're better off using Terrakion, since it's faster and hits harder with a Choice Band. The only reason not to run Scarf is to run Expert Belt or Smack Down (which would never be on a CB Set). Sub SD is possibly the only other legitimate reason to not run Scarf as well. But no, CB sucks, and you still need HP Ice anyway to function.
HP Fire leaves you very weak to Gliscor. If you are running Landorus, then you are running it in Sandstorm, which means that you will have other teammates (Celebi / Terrakion / Scizor) to take on Ferrothorn/ Forretress. HP Ice also gives you reliable damage against +1 Flying Dragons since Stone Edge is a **** move.