The developer should absolutely follow the checklist as well, otherwise he's wasting the reviewers time.

So, what you're describing is actually a good yes/no question: "Is the best algorithm for the problem used?" (or, better: "Has functionality that is available in a library been implemented by hand?", but that's not your point :) )

No, flights use checklists for even completely routine thing (especially for routine things, because that's where sloppiness will manifest itself first). For an example, if you forget to set flaps correctly before you hit the throttle for take off, you're going to have a bad time, so that's on the checklist. (Of course, these things are largely automated now, so modern aircrafts will yell at you if you don't. I think Airbuses will even override the throttle)