All of the answers to these problems are trivially easy. I maintain my stance that "game designer" is not a real job and is just a fanciful cushy position for people who were already privileged in life to pretend like they're doing hard work. Things like "do doors lock behind the player?" is not anywhere close to as hard as the very easiest problem faced by the actual programmers who are doing the actual work on your project.

"SOMEONE has to solve The Door Problem, and that someone is a designer." -- it sounds like literally thirty minutes of work per week. Just admit that your job is easy and cushy and the programmers and artists are the only ones doing any actual work. They make fun of you when you're not in the room. They add ducks to animations just so that you can feel important by telling them to take them out. You're a parasitic drain on the project, not a "big idea man". Everyone already knew whether or not that door should lock before you were asked.