My own view is very close to EJ Young, who wrote a commentary on Daniel mid 20th cent.
The seventy "sevens" are only intended to be a rough correlation to years. Do note that he doesn't use the word "years," perhaps intending us not to try to peg start-and-end points? So, all the attempts to fix a definite chronology are doomed to founder on the problems that arise from trying to get an answer to an improper question.
The three "periods" (62, 7 and 1) are generally more significant that most folks give credit for, who are only interested in the start-finish chronology.
I am perfectly satisfied that the final "seven" begins the focus on Christ's earthly ministry, in which he was "cut off" after about 3.5 years.
I am not at all dogmatic about the other "half" of the final seven, being content to think of it as irrelevant, or as extended/open-ended (ala Riddelbarger). But my preference is to think of it as the 3.5 years Titus spent in wasting the land of the Old Covenant, and destroying Jerusalem--which final ruin is alluded to in v26. In between, then, comes a 40yr, "generational" stay-of-execution, when even the slayers of the Christ are given a window of repentance.
As for Dan.11.22, the term "nageed" (prince) I think is used once in all Scripture to refer to Christ, in Dan.9:25; its use even one v later, v26, is in reference to Titus (a foreign prince). Hence, the term "prince of the covenant," in 11.22, insofar as the term is quite general, is well-worth the application to the wanton murder of one of the most (if not the most) prominent of the then-current Jewish nobility.
Remember, the focus of ch.11 is how meaningless and insignificant appear God's people in the midst of the world's conflagrations and power-struggles between the mighty-men of the earth. So, it is as if one of these bullies (too big in his own eyes to care more or less about these "hill-people") casually crushes their supreme leader like a little bug. It means no more to him than any other man's death; certainly less than a truly "powerful person's" would.
We can map these predictions (in Daniel's time) to the events that followed. But we need to remember that it wasn't as vital for the people in the days of the prophet, the after days, the days of fulfillment, or our days to know the specific fulfillments. After all, not everyone had or has access to the minute historic details that actually saw the prophet validated. If it had been important to know names (as when "Cyrus" was predicted by Isaiah), names would have been given. Instead, multiple kings bear the names "North" and "South." It obviously isn't critical know who (by name) a certain "prince of the covenant" was. Not in order to profit from the predictions.
Edit, to answer the other Q. : the fourth kingdom of ch2 is Rome. And ch2 second kingdom (silver) and ch8 ram are coeval, and the second interpretation (8:20) seals the deal, i.e. Medo-Persia.
