If you only listened to 1 video - the last one - you didn't get the flow of the entire proof that led up to it. You don't have a complete understanding. Gabriel specifically gives 3 groupings - groups of weeks (7 years). The proper interpretation recognizes that there ARE 2 gaps in between - ones that ALSO are made up of weeks of years. It's not elastic as you say. It's very specific.
You yourself gave a fairly clear summation in that last section of your proof leading up to your interpretation of the final 70th week. Yes I realize, of course, that Gabriel subdivided the 70 weeks into three groupings, but that does NOT entail a gap of any kind between those 3 groupings. You have artificially inserted gaps where
none were intended. When God gave Daniel a 70 week time span which would reveal the identity of the Messiah in the beginning of that 70th week, he never wrote of massive time gaps between any of those 3 groupings.
A 70-week time period with extensive gaps inserted artificially within it
IS an "elastic" tape measure. This makes it an absolutely useless tool for determining anything accurately. Anyone could then stretch that elastic tape measure to make it last any length of time they want, which was not what God intended.
Christ Himself said He was sent to "the lost sheep of the house of Israel" (Matthew 15:24). This was the same as Daniel 9's one week of Christ "confirming the covenant with many for one week", with the gospel going to Daniel's people of the house of Israel. Christ "came unto His own, and His own received Him not", (with the exception of the believing "remnant" of Israelites), before the emphasis of gospel evangelism switched over to the Gentile nations under the ministry of Paul the "Apostle to the Gentiles". The end of the 70th week finished in AD 37 with Paul's commission by God to concentrate his ministry to the Gentiles. We are not currently waiting for the end of the 70th week; it ended long ago.
And no, the decree year is not wrong. In fact, the decree doesn't actually matter since no one knows when (what day) it was actually made. Everyone ASSUMES it was Nisan 1. But no one knows. And no one can know since there is no historical record that states this.
The year of the particular decree most definitely DOES matter. Christ's deity as "Messiah the Prince" is at stake in this.
The day that decree was given doesn't matter, since that is never mentioned in the specifics of Daniel's 70-week prophecy.
Only the year of that particular decree is the important factor. And WE DO have archaeological evidence which helps prove the year that decree was given regarding the rebuilding of the walls and the street in front of the temple, since that evidence shows us when the 20th year of Artaxerxes' reign actually began (back in 474 BC).