Critique My Project Plan Before I Start

Your plan looks fine to you, which is exactly the problem, because you don't know what you don't know. Paste it in and it reads like a builder who's watched a hundred beginners make the same mistakes: steps in the wrong order, the tool you forgot, the safety thing you skipped, the bit you've badly underestimated. Better to hear it now.

I have written the following plan for my DIY project. Please critique it from the perspective of an experienced builder who has seen common beginner and intermediate mistakes.

My plan:
{MY_PROJECT_PLAN}

Focus your critique on: structural or safety issues I may have missed, steps that are in the wrong order, tools or materials not mentioned that I will definitely need, anything underestimated in terms of time or difficulty, and any alternatives that would produce a better result for similar effort. Be direct and specific. Conclude with a revised sequence of steps that addresses your main concerns.