That is exactly what Daniel 7 is about—suffering and vindication. The connection between the son of man expression and Daniel 7 is much stronger that Hurtado admits, at least in Mark. It is nothing like as random as he suggests.
But your list of Son of Man references in Mark draws on a much wider background than a Daniel narrative.
The authority of Mark 2:10 to forgive sins (a prerogative, according to the passage, of God alone), and the authority of 2:28 over the sabbath have little bearing on the Daniel narrative, apart from the word ‘authority’ which they have in common.
The suffering of the Son of Man is at the hands of the Jewish authorities (as well as the Gentiles), which hardly fits the Daniel narrative - 8:31, 10:33; it is about betrayal - 9:31, 10:33, 14:21, 41; it is about rejection - 8:31, 9:12 and being flogged - 10:34, giving his life as a ransom for many - 10:45 - and being raised on the third day 9:31, 10:34. These are allusions to a great variety of OT sources - Isaiah 52/53 especially, but not Daniel.
But while it is true that the early church did not make use of the expression “the son of man”, the early church certainly did make use of the narrative of Daniel 7 to speak about the suffering and vindication of Jesus and his followers.
You could also say that the early church, as reflected in the gospels, made use of a variety of stories about suffering and exaltation - a theme which are not restricted to Daniel. In that sense, Daniel has this theme in common with them, rather than being a paradigm to which they conform.
There certainly was never an argument that in certain places, the Son of Man language does refer to Daniel 7 especially, but not always exclusively, eg the mixture of Daniel 7 with Psalm 110 in Mark 14:62. That was never in dispute. But I don’t think you can take a broad selection of Son of Man references as you do and say that they find their source in Daniel 7, or even that they reflect directly a Daniel narrative.
It is the variety of OT references which are incorporated into the Son of Man statements which is their distinguishing characteristic, as Hurtado asserts and illustrates, not their conformity to one single narrative source.