I have 2 similar arched windows in our family rm and added roman shades at the straight molding since I didn't want the entire window covered, but did want ability to have privacy if wanted...
I also think I would put roman shades on the office windows... I wouldn't want long curtains on the short window and would probably put romans on both, but if you really wanted to have long panels on the one, you could have romans made up for the short window in the same fabric as the panels-

KK, you might want to look at the thread below. I and others compiled a whole bunch of WT ideas that you may find useful, including a section on WTs for arch top windows. You certainly can do floor length treatments for shorter windows.

Here is a link that might be useful: WT Ideas

Here is how we handled our Palladian window. A fan shutter for the curved portion with venetion blinds below using a deep valance across.

Hope this helps.

For the arched window, I prefer to hang the rod at ceiling height and hang panels from that level. (Basically, ignore the arch). If the panels are hung beneath the arch, it cuts off the window. Additionally, you can hang blinds on the double hung windows if you need them for privacy. As for the office windows, even though the windows are different sizes, hang rods at the same height throughout the room. In your case, I would hang the rods halfway between the window trim and the ceiling.

The problem I see, is that you have no wall space above the arch to mount a rod. You'd need to put a skinny rod mounted on the ceiling, if you wanted to go that route. The other choices would be medallions following the arch or mounting them inside, which would require custom. If you really want panels hung on a rod and don't want it on the ceiling, then you'd have no choice but to mount it under the arch. It's OK, but it does tend to make the window look squat and the wall look shorter.
In the office room, if you're going to leave the blinds there, then long panels on both are fine, as long as the rod is mounted at the same place. I think 3rd's is more pleasing to the eye than halfway tho, i.e. 1/3 or 2/3rd's of the way.

Ours are Palladian windows in the front of the house. Our interior designer did just what others have suggested here and hung silk panels on a rod above the window molding (we had to use a thin iron rod from Restoration Hardware with supports that projected out almost five inches because there are only a few inches between the top of the window and the wide crown moldings):

This is an awful picture, it's just too sunny in there for a decent shot, but this shows the few inches of clearance between the keystone of the arch and the bottom of the 12" crown. I wanted to at least try hanging the rod across the top of the rectangle, but ID said it would cut the whole thing right in two and would look terrible--- unless the window was taller than 12 feet and the proportion of the arch area to the rectangle was smaller than what we have. Our windows only reach 7' on the wall and the half round adds another two feet, so our best choice proportionally was to hang the rod above. We were lucky to find a rod that allowed us to do it!

In your case I would hang the rod from the ceiling because you have no clearance at all.

Long drapes with a cat? Or am I misinterpreting that cat tree?