It would be nice to have a current pic, with the curtains you have hung, but by way of illustration I've inserted some below. The open alcove windows seem absolutely fine to me -- I'd added a round rug to accentuate the feeling that it's its own little 'room'.

I'm looking for this Window Blinds...

I’ll happily be proven wrong but I don’t think curtains fit the room’s style. I would go with a motorized window blind. Motorized because I think you will raising and lowering daily. I’d say wood shutters but the windows appear to have a decorative design along with trim. I’d show them off! Looks like you have pretty views as well. Moving the sofa closer connects it to the tv area. My living room is set up in a somewhat similar way. Im going to try to post a pic.

Hi, I think adding a reading chair, lamp, end table all sound good. You can go in couple of directions: firstly you can think about adding two chairs with an end table, table lamp, rug and artwork; secondly, if you go for a single chair, floor lamp and end table, try and add a rug, console with some storage and style it in a way it enhances the wall that is at an angle.