I've re used every one that I have ever removed, but some of the super long, kind of thin ones have given me issues in getting them in. 12 inch long and they will go about half way to 3/4 of the way in with my driver, and then stop. I can't get them out, or in farther, no matter what I do, so I've either left them as they are and work around them, or cut them off if they will be visible, and put another one it off to the side. My guess is that they hit something or the grain of the wood binds them up so much that they just wont go any farther. I honestly don't know what happens.
Those are not the structural ones, but the thinner fasterner type screws. On the "structural" ones, they are a lot thicker and I've never had one of them give me any issues. The "structural" screws will meet code in a lot of places. I wont say everywhere because places like CA, FL and now LA are constantly changing and what was OK last year isn't always allowed this year.