A lot, if not most of “Messianic Jews” are NOT Jews. They are gentiles. That is a cult designed to ensnare uneducated Jewish souls. They put enough Jewish-LIKE stuff in their “services” to fool the unschooled, but they basically make it up as they go along. It is a complete travesty that these charlatans even touch a sefer Torah or utter any Jewish prayers. Their prayerbook is called by the Jewish designation, a siddur, but the resemblance to authenticity ends there. There are numerous references to JC in it and to the New Testament, both of which are completely not a part of authentic Judaism. The “rabbi” to which you refer is a complete fake without authentic Jewish ordination and any “Jewish” clothing they wear is simply part of the entrapment costume. It doesn’t take more than a few phrases to completely blow them out of the water as the fakes that they are. So basically, they are a cult with the express design of convincing Jews who were not fortunate enough to have a Jewish education that theirs is authentic Judaism. Kind of like trying to sell Naugahyde as leather. I make no apologies for tellin’ it like it is. I’ve seen these Messyantics in action and they are truly detestable. Anyone who thinks that deliberate misleading of uneducated Jews for the purpose of conversion is a good idea, go pound sand.
The people I met at that synagogue were at least 70% ethnic Jews, based on my observations having grown up many decades ago in a Protestant family in a 50% Jewish community, where half my school friends and neighbors acquainted me from kindergarten onward with their customs and beliefs. The "second language" in our neighborhood was Yiddish.
You have objected to the presence of gentiles at that synagogue, which is a logical contradiction, since the purpose of the Messianic strain of Judaism is to maintain Jewish traditions while also accept the teachings of Jesus, a Jew who in earthly life was called "Rabbi" by his contemporaries. Jesus taught that gentiles should be included in the salvation he said he came to offer specifically to the Jewish people. Some Jews believed then that he is the Messiah; today's Jews are descended from those who did not. This is not a judgment, but simply a matter of fact -- all the earliest believers in Jesus' teachings were ethnically Jewish.
One of the most important "gists" of those teachings is that grace or salvation does NOT depend on genetic tribe or ethnic customs, and not even upon laws, or the following of laws as a means of achieving salvation, but on surrender to God and a willingness to hear God's direction in one's life and follow those promptings. Christianity is not an ethnicity; although in my opinion, many of the divisions between various sects of Christianity have more to do with the cultures in which they originated than with definitive knowledge of the Mind of God (i.e.; Catholicism originated in ancient Rome, Lutheranism in Germany, Methodism in England, Presbyterianism in Scotland, etc.). This important teaching was one of the drivers of equality before the law that undergirded the creation of U.S. Constitutional jurisprudence, and also drove the Abolition and Civil Rights movements here and in England that worked against slavery and Jim Crow.
Although it may feel uncomfortable to you that some Jews have committed to Jesus as Messiah (Hebrew = Messiah; Greek = Christ), yet wish to retain many of their ethnic and cultural traditions from Judaism that do not interfere with their belief that the Messiah did come 2013 years ago, I would not necessarily characterize those believers as uneducated without proof. We are all familiar with today's untruthful meme that conservatives are conservative because they are not smart, or not as smart as Democrats wish to believe themselves to be. Actual research indicates otherwise. Also, in my experience, most people who claim adherence in most religions have not studied their own scriptures thoroughly (indeed, it can be the work of a lifetime), much less those of other religions.
Many who come to believe in Christ do so by way of a transcendent experience that cannot be characterized as solely intellectual. Study may come afterwards. That is what happened to me, who was born and raised in a so-called Christian family, but did not experience a whole-hearted belief until later in life.
Wishing you well along your journey.
'AMEN!!!