I was actually getting worried before the plywood went up as it felt so flimsy, but it's incredible how much strength it adds. The few cross braces I had were not enough I guess. The real test will be when I go on the roof again, as it was shaking pretty bad when I was up there. Good thing I'm not a big heavy guy.
I also had some screws that broke on me while removing them, mostly ones that were part of temporary bracing that got wet. Kinda got me worried as some of the walls sat in the rain for days before they went up so wonder if those screws got weakened. They are not galvanized so not meant to be in moisture. At some point I might toe nail the studs with framing nails for good measure. I still have some other structural stuff to do like hurricane ties and lag bolts into the floor. Though even if I don't do anything the plywood kinda does hold everything together anyway.
Also I bought JUST enough plywood as I actually used the last sheet. I have lot of scrap that is rather large and can be used for other projects though. Come to think of it I actually misscalculated the plywood as I originally wanted enough to double the floor thickness, but decided to leave that out and only do it once the shed is fully built. Glad I did.
I'm just so happy with the result so far, like to consider I went from digging a couple holes in dirt to a semi weather proof building with a door! Took way longer than it should have because of the weather though. But seeing how much work and time was put into this, it made me realize if ever I want to build a house or cottage or any larger structure, I will hire out the main structure/shell. Then I can do everything inside without having to worry about weather.