This is a great idea. Thanks!

As one who has just the most superficial understanding of C++ and no other languages, I think what I would find the most useful is a "plain English" explanation of the general structure of the code used in pins. As in, "These are the general schemes used, and this is a typical implementation" breaking things up into such categories as "multiplayer, scoring, reading a matrix, firing coils, etc."

I feel like you could then leave the specifics to the designer, but as purpledrillmonkey said above, when you don't know what you don't know...maybe I'm all wet?

Pseudocode would be fine as well.

I would see it as three levels of complexity:
General- What we do
General- How we do the above
Specific- Examples of how

Regardless, I appreciate all the effort being put into this!