Whether a person believes that Jesus Christ had super powers or was the son of God is up to him or her. At this point though, most religions that existed at the time will attest to the existence of at least the man. He may have not been quite as legendary as the stories, but what man is truly the reflection of the stories even he tells about himself? "I caught a fish that was THIS BIG."
The entirety of the Hebrew laws (ceremonial/levitical-mundane/civil) are figurative in archetypal terms of the expected messiah and the rule of God's Kingdom on Earth as it is in Heaven. This is supported in the new testament See Hebrews 8:5-Hebrews 10:1 and in several more places as well as by traditions of Jewish origin.
No, the Mishnah does not reference Jesus. Jesus is not a part of Judaism. He is part of Christianity. It wouldn't really make sense to reference him in the oral laws and traditions of Judaism. The Mishnah deals with Judaism and laws, so there would be little to no reason for a reference to Jesus.
No, I do not believe that the Mishnah references the existence of Jesus Christ, because the Jews do not consider the life of Jesus as part of their Bible, nor do they accept him as the Messiah. The Mishnah is a collection of Biblical teachings, a sort of "oral Torah" to study Jewish traditions. Christ is not part of that tradition.
People like to read into ancient text to find the meanings that they want to find there, and this case is in no way thinking. Jesus was a contemporary of many of the people in the Mishnah time period, but there is little reason to think he's in there, considering the type of people who wrote it.