The use of "Christ" in the KJV is a defect of the Greek source they used. The emphasis on the plural "you" used as a subject is more like "you yourselves."
The negative is a negative of opinion that has the sense of "not want." It is not a command, but it is the negative used with commands.
The "your" used with "teachers" is unusual, for Jesus, because it comes before the subject. He does this to emphasize possession, the sense is "one is yours, this teacher."