An absolute improvement would be more difficult courses. Drop the golf-course type courses. Whether it's a 2K loop or 4K loop doesn't really matter to me. While I see the benefit of a longer 4K loop, I see why a 2K loop might be preferable with respect to making a spectator friendly course. Of course, there are ways to make a 4K loop as spectator friendly as a 2K loop by having parts of the loop pass near a central point.
I know you've never been a big fan of the nationalistic approach to many of the championship events and I agree. I'm not sure how you improve on that in this case if the problem is the dominance of Kenya and Ethiopia. Combine the two most dominant teams and you have an even more dominant team. Of course, that frees up the team silver medal but creates no team race for first. I have mixed feelings on that.
What about following the lead of some of the indoor T&F meets and the NCAA events we've seen recently and offer a live stream online? Throw some ads on there and you have a new revenue stream.
I do think these problems could have been looked at as opportunities to innovate and the choice, instead of innovating, was contraction. I won't pretend to know what the innovation should have been but you offer some interesting ideas. What I do know is there have to be some ideas out there, as you prove, and they should have at least been considered.