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.

I think you should stay with a simple pattern for draperies. Possibly a pattern incorporating the white trim and warm yellow walls. This would be soft and understated and something that you wouldn't get tired of easily. Other colors could be introduced with accessories.

I faced the same issue when i brought a new house and had to use my old double door refrigerator. The refrigerator was white in colour but after 6 years of usage it turned yellow . I simply brought a 700 Rs decal sticker from aliexpress and voila its turns out really well for my house. Attached some pictures for your reference. Now talking about the almirah i would have painted it some bright neon colour or maybe matt black ( colour depending on what would look good in your house ) to make it the show stopper of the house. Good luck and post pictures once its done!!

I would take away those top arches and have builtins either side of fireplace, have the tv placed on a shelf on the built in, like in the pics, you don't have to have it above the fireplace, if room is small it will feel like it's coming at you lol. Panel above fireplace and hang some artwork or a nice mirror. Quiet like the builtins with the back wall painted