I agree with Geokid. I design and build custom closet organizers for a living and the layout you've described is one of the most challenging. The only way to utilize the space is to either put 24" deep shelves in both corners facing toward the center of the closet or to add a hanging bar going across with the clothes facing toward the center of the closet. Yes, it will be awkward to access these spaces but not as awkward as if you build everything across the long wall all the way into the corners. Use these two end walls to store items that you don't access very often like suitcases, Christmas boxes, gowns, etc. Best of luck!

I would do a switchback staircase with a landing. You could keep it along the outer wall...or move it so it is inline with the hallway. It could open to the living room or the entryway. You would then have room for both a coat closet as well as another room space if you better utilize your entries on the lower left of your plan. (which are also taking up a lot of space! By using a switchback staircase to the basement, you are keeping the staircase space as part of the volume of the entry/living room space, making it feel larger than it really is.

So the doors open in to the space... Would you be opposed to removing them? Sounds like this may be more of a relaxing space to hang out and play on the computer, than a true "work from home" office. You'll lose square footage if you do a built-in, but you could put one on the north wall. Float the desk in front of it facing the south wall, and angle a chaise at the window facing the view.

I am not sure. I have another idea but I don't know if it is any better: What if the only full wall is beside the hallway then have a built-in 3'0" high (just enough to fit your fridge below). I would make that built-in 18" deep and run it all the way on that tv wall. You can put your tv on where you have it now and have storage on the left of it. On the right, it would be your fridge with some storage to the left for glasses etc. I would consider making the top of the built-in all the same material and put a table mat where your fridge is to protect the top. You can have shelves on the wall if you wish but I think I would not. Seeing the wall recessed compared to the bottom where you have your built-in would make the room feel bigger even though you use some floor space for your built-in. I would also make your closet 6'6" wide and deal with the problem of 2 persons being in that room at the same time. I think one can choose their clothes while the other is taking a shower. I think it is worth that compromise to keep your bathroom and office wider.