nben1, Hi, I would open a 42" to 45" opening on both ends of the wall between living and study. That would leave room for a TV with components in a unit below. A desk would be nice in the back left corner of the study, with art or photo above, a chair in the back right corner and a chaise or small sofa on the wall behind the tv. That would make everything look roomier and make the study more inviting. In the living an L shaped seating would be nice floating with a small console behind. Good luck!

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 agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

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