There's so much that could be written about this accident. I think the most useful takeaway for pilots is to listen for the relative workload of your controllers and use that to modulate your focus on traffic scanning. Sure, you're supposed to always be scanning for traffic, and you're always responsible for traffic separation in VFR conditions. In the real world, time spent on traffic separation decreases time available for checklist usage and precise control of altitude, speed and position, so you have to adjust priorities based on conditions.
Our controllers at Palo Alto are amazing cat herders. It's totally normal to have 6 aircraft in the pattern, but they also do have some limits (perhaps they have written limits--that would be a good thing), and you can tell when they need to unload. When things get busier than they are comfortable with, in-bound aircraft will be told to hold and aircraft in the pattern will be told to make full stops. Within about 4 minutes, the situation is back under control. If you hear this happening, you need to be extra sure your traffic to follow is really the airplane passing off your wing before turning base.
Flight Level Engineering added fly-by-wire to a Ryan Navion, and they made all the control parameters accessible to an operator in the right seat. The plane can be made to have the controllability and stability characteristics of any other aircraft (within the maximum pitch, yaw, and roll rates of the unmodified Navion) or be made just somewhat difficult to control as an educational tool for test pilots and flight test engineers. It's also about 1/3 the cost of doing a similar program in the Calspan Learjet. Save your money!
I understand getting lost happens to solo students with some regularity, though I think it happens more in flatter parts of the country. In the SF Bay Area, the presence of large terrain features makes it harder to become profoundly disoriented. These 5 tools are not complicated, and if you understand them, you'll never get lost. (That's a good thing, because I bet being lost in an airplane is damn scary.)