Wow, now this becomes very personal with lots of different views. With that said, here is my view.

Transmission - I do not do anything here so I want one that seems solid.
Body - Why start with something that needs money spent here?
Interior - If you want to sell things to recover money and only if it is in great shape to allow you to do it. If it is bad but the price is low enough, who cares.

Everything else on your list - Who cares.
Engine - I would never put a car on the track without having the engine redone including water pump, hoses etc. I replace the radiator as well due to the temps we see here in the summer. I simply don't like the idea of not knowing the history of important bits and pieces.
Suspension - I replace wheel bearings, shocks, bushings, torsion bars, etc so the condition of the original suspension is not a concern for me.
Brakes - Who cares, I replace the soft lines with ss and either rebuild all of the calipers or buy them from Paragon. The rotors are replaced as well as the pads as part of the build.

Great post. You will get lots of different opinions and perspectives. I await others views on this topic.

Jim "Big Dog" Foxx