"I went to work in an office that had a pocket door that never worked right because someone had driven nails into it at some point and it was never the same after" (palimpsest) Yes. This happened to us when DH nailed the baseboard on the wall between the laundry and kitchen. The door came off track. When we renovate I will replace or remove. However, this was builder grade. On our extension I added three pocket doors. The one I had put in for the powder room is a solid core door, not thinner than most doors, as I wanted as much sound-dampening as possible with such a device. We used Johnson Hardware - not the home depot variety which runs $ 40 or so, but commercial grade. Look at the Johnson site under 1500 Commercial Grade and you will also find non-standard size frames (door max thickness 1 3/4"). Use a good carpenter.

I'm going to say none of above (if pocket doors not an option).... I see french doors in new construction offices all the time and all I can attribute it to is "what everyone is doing" because from a practicality issue it makes no sense to me. Most people's offices are for working in and are functional and private and often times, messy! Why would people want that to be "open" to everyone? You certainly don't want your guests to see it and it is even unappealing and even stressful to look at a space covered in piles and clutter. I know everyone's office is not this way but trust me :), most are not the tidiest rooms in the house! Put solid doors that offer noise control and privacy. Also gives you other options if for some reason it needs to serve another function at any time- i.e. guest room.

You said you've already made a decision but for others in the future....transoms in a bedroom complicate window coverings. We are renting a house with plantation shutters on the windows and nothing on the transoms. Dawn is pretty darn early in the summer! If you are a late sleeper or need to sleep during the day, consider how to cover the transoms.

Why not just paint that upper white part the same blue as the door? That will provide same or similar visual effect as your original door. Keep it simple. If you put a header on it, its going to clutter it up and draw attention to it and make the space look more awkward, not less.... besides being a total stylistic mismatch to the house and the door. I dont know if Id put anything in there at all - just blue to make it all look like a single, unified space. If you are replacing the sconce, get one thats simple, discrete, and doesnt draw attention to itself The door itself (is all the style statement you need to make. Its a simple, boxy brick house with a stylish blue door. Thats all you need - boom, done. Sometimes less is more.