sometimes freeze (often) fail , so dont depend on it unless you fight lower level enemy.
to prevent auto-attack waking up an enemy that already sleep, spam dodon barrage skill when casting sleep skill. after that, cancel the dodon barrage...
This has worked BEFORE the patch where they've removed cancelling. Sady this can no longer be applied as cancelling is gone.
Freeze is technically a type of debuff, so Hit rate does not directly contribute to it's effectiveness.
A matter of your debuff succeeding or failing will entirely depend on your FOC Vs Opponent's DEX/Resistance. Crane has a naturally high FOC stat along with the passive, so it should have no problem connecting those debuffs.
This may be superstition, but it is suggested that the skill would only work if in a combat state.
Then again that was the KR version of the game, so they might have things different here.