Good list, I have intuitively realized all of these except for (3). I agree with the author: cheap experiments to figure out a grand architectural plan, then executing fast without needing to wait for input is the right way to go. "Automate everything that's easy" is also important, but I'd extend it and say you probably should try to automate things that are hard too: it's worth spending a great deal of time on it simply due to how crazy valuable the returns are. But I guess I should look more into end-to-end testing.