Wow, okay. Let's go over some fundamentals. The Jesus of gMark is precisely, emphatically not a Davidic messiah, not "king of the Jews," not a rebel against Roman rule.
It doesn't look this way to me at all, since Jesus
says he is the Messiah in Mk. 14:61-62, which, given the context and its equation with Daniel's "son of man," I take to mean "king of the Jews":
Again the high priest questioned him, “Are you the Christ [aka the Messiah, whether "Davidic" or not], the Son of the Blessed One?”
“I am,” said Jesus ...
And I think what he says next makes his ultimate intention clear, since he says that
you (i.e., the Jewish leaders who were favored by Rome) “will see the Son of Man sitting at the right hand of Power and coming with the clouds of heaven.”
And what does Dan. 7:14 say about the "son of man coming on the clouds of heaven"?
And he was given dominion, glory, and kingship, so that every people, nation, and language should serve him. His dominion is an everlasting dominion that will not pass away, and his kingdom is one that will never be destroyed.
So it doesn't matter if Jesus thought of himself a "Davidic" Messiah or not (though I think he did, or at least that his family thought so, to judge from Hegesippus' account of the grandsons of his brother Jude in EH 3.20.1-2:
Of the family of the Lord there were still living the grandchildren of Jude, who is said to have been the Lord's brother according to the flesh.
Information was given that they belonged to the family of David, and they were brought to the Emperor Domitian by the Evocatus. For Domitian feared the coming of Christ as Herod also had feared it. And he asked them if they were descendants of David, and they confessed that they were.
But in any event, as we can see, by equating himself with Daniel's "son of man," Jesus is effectively calling himself a king ("Davidic" or not) who will soon rule over "every people [and] nation," which would include Rome, right?
This is why the Donkey ride into the Temple, when the crowds proclaim that he will restore the kingdom of David, results in the nothing burger that you referred to in 11:11. It is why Jesus teaches overtly that the messiah is not David's son (12:37).
There are other explanations for these verses, which I don't have time to go into right now (though Ben has discussed the first one upthread).
And it is why Jesus gives different answers to the "Christ question" posed first by the high priest, then by Pilate: they ask him two different questions. You missed this crucial fact when you equated "Christ" with "King of the Jews." Jesus says that he is "Christ, son of the blessed one," and then prophesies the coming of the Son of Man. To Pilate he only says "you say that I am" the King of the Jews.
Can we at least agree that the Greek word "Christ" is equivalent to the Hebrew word "Messiah"?
And Daniel 9:25 equates the word "messiah" with the word for "prince" (nagid), which means "leader, ruler," and it is also used to describe David (like in 1 Sam. 13:14):
Know and understand this: From the issuing of the decree to restore and rebuild Jerusalem, until the Messiah, the Prince …
The Lord has sought out a man after his own heart [i.e., David], and the Lord has commanded him to be prince over his people ...”
https://biblehub.com/hebrew/5057.htm
The Jerusalem mob demands the liberation of Barrabas, a rebel and murderer (representing the lestai, sicarii). That is, the type who would eventually lead the revolt in 66. But they reject Jesus ...
Yes, because they were stirred up by the chief priests (who were favored by Rome).
... the messiah who preached a humble Judaism of righteousness (12:28-34), rejecting sacrifices and purity laws ...
How is Jesus' response in Mk. 12:28-34 a "humble Judaism"? He just answered the question that was posed to him, "Which commandment is
the most important of all?" by citing verses that are standard in Judaism (as the scribe acknowledges):
Now one of the scribes had come up and heard their debate. Noticing how well Jesus had answered them, he asked him, “Which commandment is the most important of all?”
Jesus replied, “This is the most important: ‘Hear O Israel, the Lord our God, the Lord is One. Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’ The second is this: ‘Love your neighbor as yourself.’ No other commandment is greater than these.”
“Right, Teacher,” the scribe replied. “You have stated correctly that God is One and there is no other but Him, and to love Him with all your heart and with all your understanding and with all your strength, and to love your neighbor as yourself, which is more important than all burnt offerings and sacrifices.”
When Jesus saw that the man had answered wisely, He said, “You are not far from the kingdom of God.”
Shema Yisrael (or Sh'ma Yisrael; Hebrew: שְׁמַע יִשְׂרָאֵל; "Hear, [O] Israel") is a prayer. It is also the first two words of a section of the Torah, and is the title (better known as The Shema) of a prayer that serves as
a centerpiece of the morning and evening Jewish prayer services. The first verse
encapsulates the monotheistic essence of Judaism: "Hear, O Israel: the LORD our God, the LORD is one" (Hebrew: שְׁמַע יִשְׂרָאֵל יְהוָה אֱלֹהֵינוּ יְהוָה אֶחָֽד׃), found in Deuteronomy 6:4. Observant Jews consider the Shema to be the most important part of the prayer service in Judaism, and its twice-daily recitation as a mitzvah (religious commandment). Also, it is traditional for Jews to say the Shema as their last words, and for parents to teach their children to say it before they go to sleep at night.
https://en.wikipedia.org/wiki/Shema_Yisrael
The Talmud tells a story of Rabbi Hillel, who lived around the time of Jesus. A pagan came to him saying that he would convert to Judaism if Hillel could teach him the whole of the Torah in the time he could stand on one foot. Rabbi Hillel replied, "What is hateful to yourself, do not do to your fellow man. That is the whole Torah; the rest is just commentary. Go and study it." (Talmud Shabbat 31a). Sounds a lot like Jesus' "Golden Rule"? But this idea was a fundamental part of Judaism long before Hillel or Jesus. It is
a common-sense application of the Torah commandment to love your neighbor as yourself (Lev. 19:18), which Rabbi Akiba described as the essence of the Torah …
http://www.jewfaq.org/brother.htm
And Jesus certainly does
not reject sacrifices or purity laws, he just says that the above commandments are
more important than sacrifices, which is also a standard Jewish opinion that pre-dates Jesus, and in fact he castigates the Pharisees for disregarding the Torah in Mk. 7:8-13:
" ... You have disregarded the commandment of God to keep the tradition of men.” He went on to say, “You neatly set aside the commandment of God to maintain your own tradition. For Moses said, ‘Honor your father and your mother,’ and, ‘Anyone who curses his father or mother must be put to death.’ But you say that if a man says to his father or mother, ‘The help you would have received from me is Corban’ (that is, a gift committed to God), he is no longer permitted to do anything for his father or mother. Thus you nullify the word of God by the tradition you have handed down. And you do so in many such matters.”
Wouldn't Jesus be a hypocrite if he "set aside" and nullified "the commandment" and "word of God" too?
And I think Mt. 5:23-24 perfectly encapsulates what Jesus says in Mk. 12:28-34 above:
Therefore if you are offering your gift at the altar and there remember that your brother has something against you, leave your gift there before the altar. First go and be reconciled to your brother; then come and offer your gift.
... and affirming the payment of taxes to Caesar.
I answered this one upthread. You may not agree with my view, but as I said, I see Jesus' response as major insult to Caesar (and one that in and of itself disproves the Flavian hypothesis, since it says that Caesar is not divine).