Free. In practice whatever a given janny doesn't like gets the boot. The moderation can get REALLY schizophrenic depending on time zone, and there are persistent rumors that certain boards are controlled by groups of interest (notably the cesspool known as /pol/ is very astroturfed).
There's also a "janitortest" account in the leaked list @4chan.org so who knows if there was just a shared password flying around...
Free isn't a kind of speech, it describes a condition under which speech is performed. Their question was what kind of speech is being alluded to.
Their question was a gotcha attempt, and a misguided one at that, hence the answer specifically not playing along.
Once you've made this many comments about it and are still unwilling to describe the acts you're defending I would certainly call that playing.
You're clearly confused. This conversation is about 4chan jannies, not reddit moderators. They don't ban you for posting racial slurs or fascist rhetoric, or any other traditionally offensive material.
Make a thread about Chinese naval buildup or related strategic developments in the Pacific on /k/; banned for "off topic". Get into an argument with a user who turns out to be a janny; banned for "trolling". Respond to a funny /tv/ thread memeing on some TV show, banned for "responding to off topic threads". Post a dozen pictures of rockets in the spaceflight general being raided by some /pol/tard who thinks space is fake, get banned for "spamming".
The jannies are arbitrary and capricious. Three day bans can't be appealed so they hand them out like candy.