1. I hope that you can use at least some ideas (as a concept), and to combine them with other ones.
2. Layout and sections were generated from the 3D model (like conceptual design)
3. After selecting the version, you will need a structural design; architectural detail design, then you will have budget list.
4. The location of the ladder pointed out by you has insufficient space and is unsuitable for structural and architectural reasons.
5. I wish you a successful choice , the project was pleasant for me. For the next step you will need a local licensed designer (i have license only in Europe :). I wish you success.