If the british government had been more belligerent in 1938, so would have been the french. That way, Hitler does not get the carte blanche to invade Czechoslovakia, which builds up its defenses for a hypothetical future second attempt by Hitler to press on them. Maybe Hitler, in a fit of overconfidence, still tries to declare war and invade despite anglo-french protests (which puts me in the "no" camp in your "pacified Hitler" poll), but then he'd be quickly deposed by the Oster Conspiracy.
With no czech tanks or gold in the german army, Germany does not get the confidence nor initiative to invade Poland. Therefore, no WWII. But that's mostly a semantic issue, since a war between Germany and a Franco-Czechoslovak alliance could be interpreted by some as a continuation of WWI.