Its rare for Robert Heinlein to be called a communist these days. As an ex-military man (semi-real service here -- navy, battleship service and all that), who at times made suggestions like a person should not be able to participate in the political process until they've served military service, its not really fitting. Someone who believes in economic freedom as much as Heinlein is rarely classified a liberal these days (though it certainly fits the classical liberal name). Yes, he believed in social freedoms as well (like group marriage being legal), and was quite skeptical of mysticism and religion, but I'd call him a libertarian if I were to call him anything at all.
Those who refuse to support and defend a state have no claim to protection by that state. Killing an anarchist or a pacifist should not be defined as 'murder' in a legalistic sense. The offense against the state, if any, should be 'Using deadly weapon inside city limits,' or 'Creating a taffic hazard,' or 'Endangering bystanders,' or other misdemeanor.

However, the state may reasonably place a closed season on these exotic asocial animals whenever they are in danger of becoming extinct. An authentic buck pacifist has rarely been seen off Earth, and it is doubtful that any have survived the trouble there .. regrettable, as they had the biggest mouths and the smallest brains of any of the primates.