It would be nice if you could add a photo showing more of the wall where the window is located.

I would want to remove the half circle window if at all possible.

Here is more of the wall. Not an option to remove the other window

where you have it is fine. no lower, no higher. I would take them all the way to the right corner and as far left as you can

if you added some trim molding around the window, it would add some pizazz to it. it's somewhat underwhelming as is.

I had a feeling that removing the half circle window wouldn't be an option - and that's when I thought there was only one.

In order for a pro designer or knowledgeable non pro to provide the best advice, they will probably need to see more walls - this room appears to be open to other rooms (at least there is more connected wall to the left).

Do you have curtains hung in other areas connected to this room? Is this the only room with a vaulted ceiling?

Sorry perfect answer say goodbye to the arches and even moreso since you have 2 very different spaces to add window coverings . But id not happening then you will need to hang thos edrapes as shown and do something the same for the patio door and deal with the function for that

I’d take the focus off the upper windows and the large gap. Aim for a lighter, more modern feel by adding matching (light) blinds on doors and window + drapery (rod a bit lower).

I would pursue a solution more like this with Roman shades and drapery panels.

I like your idea of lighter panels.
The whole wall is very tricky because you have to take into consideration the ceiling slope, the upper windows, the patio door and the windows.
I'd personally get lighter panels, hang them lower and get a neutral rod. You'll add a layer and texture without competing with everything else going on with the wall.
Maureen's examples are nice.
Keep in mind that unless you are getting custom panels you will have to work with the readily available panel lengths.

I'm not a curtain girl, so I will not comment on how to dress the windows.

But.....I gotta say....that telling someone who is asking about curtains to "remove the window" is a lilttle strange. OH yeah, let me just rip the wall apart, reconstruct it, and then decide about curtains. NOT. Be real!