Ok, so I think all this is getting sorta carried away from the main point.
Structure, when it comes down to it is, basically beginning, middle and end (this also applies to scenes in general but that's too minute). How much goes to each is dependant on your story's genre and style and conventions. Generally, your beginning and end should be shorter. If you had to put a ratio on it, something like 1st quarter, set up/beginning, 2nd and 3rd quarter middle and last quarter end. You 2nd quarter should be build up and adventure and the 3rd quarter should be all build up to your climax, and then your last quarter would be recovery and wrap up. How uneven these quarters are, of if there aren't extra bits, depends on the specific set up of your story. Some will skip almost everything after the climax, some will go on forever, some will skip straight to the build up and ignore a slower "normalcy" type opening. This is structure.
When talking about flow, that's a lot more about presentation and how these things connect to each other and if you will present them connected to each other. And much of that is about execution. Consider this like the scene to scene, shot to shot editing in the film. You don't notice when it's good, but you do notice when it's jarring (hopefully because it was intended to be and not by accident).