I haven't read the post yet, but I'm too excited not to reply. Welcome to the addiction!
Edit After reading: I've had roughly the same experience with trackday schools. I usually sit in anyway if it's free, and in doing so I also noticed that there is quite a bit of variation depending on which coach(es) are assigned that day. Track maps also seem like the sort of thing that any sensible school would include, but that's also hit or miss.
I'm definitely with you on the second set of wheels/rotors/sprockets/pads issue. If it's worth having spare wheels, it's worth the time spent swapping them in my opinion. Convenience items like captive spacers and pull cups suddenly seem like a useful investment.
I also sort of expect to forget something each trip. This past weekend I
- Bought food and water
- Charged cameras, ensured SD cards were empty
- Neglected to pack water, food, or cameras that I had so diligently prepped