Has anyone structured a flowchart. A yes or no answer would be great.?

Yes. Matter of fact, quite often. I spent years debugging complex one-off industrial manufacturing machine designs after they hit the floor. It wasn't uncommon to go back and rewrite parts of a flow chart to make troubleshooting easier for the people who ended up having to maintain these machines in the factories that ordered them..Whether it needs to be rewritten or modified is decided by the complexity of the problem.

Sometimes rewriting it from the top can be very complex and time consuming. And if if you dont have good luck, it might also turn out to have more errors. Developers usually start off with raw code, and they face the difficulty later with no proper design. I dont say the flow charts is a must, but it will be useful for if someone else takes up my place who wants to work in the piece of code i have written. It would give him a clear understanding of what is happening, rather than breaking their heads looking at the raw code.