Have you thought of using wall vinyl to add some expression to your room? It really does add that little bit of character and warmth, and can always be removed without damaging the walls. The awesome part about these is that they look like they are painted on the wall- I have a bunch in my house! Plus you can get them in virtually any color to go with your rust walls. I would suggest a dark chocolate brown or maybe a light cream. Check out the ideas before, and let me know if you maybe would like to design something custom! You can browse through the stock designs at: http://erins.uppercaseliving.net

A thick concrete wall can keep your house cool. Steel will make your house hot unless you insulated the walls well. Insulated walls don't work very well in a flood zone. When they get wet, you need to tear them apart. You will need concrete for the foundation most likely unless you are driving steel pylons. There is probably a combination of the two that will suit your needs best. It would be helpful to know what you want to achieve by using steel. There are advantages to both. Steel floors can be cantilevered further. It is easier to make bigger window openings. Floor and roof spans can be lighter and quicker to build with steel, but the roof will get hotter and therefore need good insulation and need to be well ventilated. These are just general assumptions of certain building practices so that you know what to ask people where you live. The practices and resources vary from place to place and building something for a specific purpose can change the benefits of one material or the other. My best guess is that you will probably want to use both.

How do you decorate your place, what kind of style, colors, and feelings? That will greatly influence the type of door you might want. Also, think of your budget, and whether you want to install it yourself or hire a professional (you don't need to tell us, just keep that in mind). Then look around Houzz, in the products page, they have lots of interior sliding doors and hinged ones, from elegant frosted glass in a dark wood frame, to rustic reclaimed wood planks. You may not want to purchase that exact model, but it might give you a better idea of what would fulfill your airflow needs without sacrificing style.

Mohammad. I understand your program. You may be lost in the details at the moment. Please do follow and trust the advice given here by all these people. You are about to embark on a reasonably expensive journey. Get professional help with someone who you can sit down at a table and brainstorm with them your ideas and intentions. There are Architects and there are professional building designers who are members of the American Institute of Building Design (AIBD) who are well versed in projects such as yours. I personally love a design challenge. After 38 years designing homes and special use buildings I enjoy this type of challenge the most. I am in Ohio and may not be close to where you are but I am sure with a little investigation you will find the best design professional for you.