Your last suggestion (that Jesus actually did not identify to the apocalyptic "Son of Man") might work for some isolated sayings, e.g. Mark 14:62//: "you will see the Son of Man seated at the right hand of the Power,' and 'coming with the clouds of heaven.' "
But imo it is not the most natural reading of those passages in their extant context, and it doesn't apply to any of the Gospels as a whole -- think especially of sayings like8:31//: "Then he began to teach them that the Son of Man must undergo great suffering, and be rejected by the elders, the chief priests, and the scribes, and be killed, and after three days rise again."
This doesn't corespond to the common Jewish representation of the Son of Man in heaven.
So it all boils down (again!) to the question of "the historical Jesus behind the Gospels". If you assume there was such a character and he shared contemporary apocalyptical views, he may well have referred to another as "the Son of Man" -- and then the Gospel writers gave an entirely different meaning to those sayings by identifying him to "the Son of Man".
But this is pure (and imo unnecessary) conjecture. To the Gospel writers Jesus was "the Son of Man" -- a status dependent on Jewish apocalyptics but modified to suit the role of the Christian Saviour.
I have an analogy that might fit.
You are tracking an animal. You follow the tracks to an intersection where a lot of other tracks intermingle. The trail from that point becomes confused by the overlay/underlay of other spoor.
The Bible is layers and layers of spoor. Plus, tampering!
Following a trail like that without abandoning it requires that the tracker have a lot of confidence in himself.
This is probably the chief cause of so many opinions! It seems like every confident reader of scripture just knows he himself possesses the very talent, wisdom and acuity it will take to corner his quarry and take home the prize!
Here is where I first developed the core idea of what I am dealing with when I approach scripture. I'll share it with you.
Too many people got to the trail before I did and messed with it! The evidence is corrupted beyond reckoning.
Where does this leave me?
Scholarship consists of very bright and honest trackers giving their opinions and compounding the confusion with (often) an agenda.
We assume we are actucally tracking an identifiable beast. But, it really is only an assumption.
We assume the old stories of what kind of critter it is have some ring of truth to them. But, they may be largely fish stories which have grown and colored beyond possibility.
Jesus may have been one person or a composite of many such people. He may have been a Jewish Apocolypticist (?) or not.
The "real" Jesus might be like Robin Hood or King Arthur. Or, Jesus may be more like Brer Rabbit.
If there really were any definitive answers we'd all have stopped playing this intellectual game long ago.
I think it is the amorphous nature of the allure which draws us in like staring at splatter art reputed to be a masterpiece. We can all project our meaning on to the canvas willy nilly and be as right (or wrong) as the next expert.