You could build out above the window with a single 1 by 6 board (or whatever fits), then attach metal, wood, accordion or cellular blinds.

The magnets made to hang wreaths are very strong and come with a hook.

Hi Michelle - Thanks for the comment. I would prefer not to have any window coverings either but we get some sun through that window and my husband thinks we need to block the sun from fading the floors and furniture. Have you had that issue?

1. The amount of UV rays penetrating the window is dependent on the insulated glass unit used. Some IGUs incorporate glass such as Cardinal LoĒ³-366 that block nearly all UV rays.
2. If you want to block UV without shades, you can install window film.
3. I have a window with a drywall return (drywall surrounds the window in the way metal surrounds yours). I installed Bali cellular blinds. Bali supports up to three blinds installed on one headrail. This means that you could have one blind each over the two operable lites and a third blind over the fixed lite but have only one headrail that would extend the total width of the window.
4. If the Bali blinds had a basic cords, the "stacks" (the height of the shades when they are fully open) would be minimized and as much of the glass as possible wwould be visible. I would suspect that the stacks would be shorter than the height of your window frame (i.e., no glass would be covered). You can ask the seller for the height of the stacks.
5. Yes, you would have to attach the shade to the return with screws.