The very large, and profound difference I see here is this: Jesus is God. When Jesus tells you that there is a gap in Isaiah, we can go, "well alright then"...even if there is no direct and specific reference to a gap in the scripture.
However, when it comes to the gap that Dispensationalists insist is there, but is also not directly or specifically mentioned, they do so on their own authority, without, as far as I can see, any weighty biblical evidence to back it up.
Bit of a difference.
Sorry, but no it is not 'clear' that there is an implied gap. There are other, biblical interpretations for the '70 weeks'. And while none of them are what I'd call perfect, they still can be argued from a biblically faithful standpoint. Your view, with it's 'obvious/not obvious' gap is just another interpretation that has it's strengths and weaknesses.
From my point of view, in cases such as these, weighing up the 'viewpoint' that has the least weaknesses and assumptions to its name, is the one that ought to be looked at most seriously. And in my opinion, that is not the Dispensational model.
Again, the problem I have with this is the outright assumption that it has nothing to do with the Church; especially when we come to the NT and see that these things are not so easily divided anymore. Where once 'the temple of God' was clearly a reference to the actual temple, in the NT we see it referring to the people of God; the Church. We see in Revelation that the Church, the bride of Christ, IS, in a way, described as the New Jerusalem, coming down out of heaven. We see references throughout the NT to the people who are the 'children of promise'...those people who are truly recieving the promises given to Abraham. Not those of the flesh, but those of the spirit; the Church.
So, in fact when we look at it closely, we see that the Church has been grafted into Israel, and that much of what is talked off and promised in the OT about Israel therefore does apply to us.