Wow, this is tough because of the double doors! I think what you need to do is make two sitting spaces in your long living room. One sitting area will be in front of the TV and the other will surround the fireplace.

The fireplace sitting area is a little tricky because of the doors. Here's how I would do it: I think I would position two chairs at an angle, facing each other, just in front of and on either side of the fireplace. The one to the right would be slotted in where the bookshelf is so that it doesn't interfere with the doors. You could also add a side table or two. So these two chairs, and the fireplace, would serve as a sort of conversation nook or reading area.

Then, to make that configuration flow into the other sitting area better, flip your sectional to the opposite wall, and the cabinets to their opposite wall (you might need to separate the cabinets a bit--doesn't look like they'll fit, but they're modular yes?). You'll also need to push the sectional toward the wall with the door so that you have enough space between the two sitting areas. Also might want to add a sofa table along the back of the couch arm that would then be facing the fireplace sitting area, not because it's necessary but just because it could look nice/hide the back of the sofa. Instead of a sofa table, you could also do a cabinet, tall plants, a bench, what have you.

That's what I would do if you wanted to keep your same furniture. Obviously lots of different options if you wanted to replace it, but however you do it I think two separate seating areas would be a really lovely use of space.

We were thinking along the same lines as you. We are looking at new furniture. Again the flow and how to use is our main concern. Thank you for your ideas.