What happened during the 2nd 3 and a half years after Jesus death (to complete the 7) and how did that fulfill Dan 9?
Is there any question in your mind that Daniel 9 is referring to the death of Christ? It’s in the middle of the seventieth week. That’s just to explain that time period which both agree is dated precisely by Daniel’s prophecy. There’s not really an issue with the “last half”.
As far as the fulfillment of Matthew 24, if you read the historic account of Josephus regarding the siege and destruction of Jerusalem, you will see that the “abomination of desolation” in the temple courts may well be covered by an incursion of a Roman cohort into the temple area. Their standards, carried into the area, were depictions of pagan gods. The cohort was subsequently withdrawn. Those inside Jerusalem who regarded that desecration as a sign would have had an opportunity to flee Jerusalem prior to the final destruction.
Throwing away the dispensational filter and reading Matthew 24 in light of the historic reality confirms everything Jesus said. We don’t have to twist the meaning of “this generation”. That generation did see Christ return in judgment for their rejection of Him.