I would not put window treatments, natural light is so coveted and those are windows you want to show off!!!

I agree--no further window treatments unless you want to replace blinds with roller shades.

If privacy is not an issue, I wouldn't put any covers on these windows. They are magnificent and you are so fortunate to have them. I'd remove the blinds (but that's just me - hate blinds) on all windows - they cheapen a room's look, no matter how expensive the blinds are.

If you like this look, it could be nice to do this around the side arches of your large arched window (without the valance added to the top of the curtain). I'd go for simple roman blinds in a coordinating fabric for all the other windows. I don't think the venetian blinds are doing your windows any favours. The grid pattern and the stripes of the blinds is just too much.

I dont think valances or roman shades are appropriate for this shape window. If your goal is to soften, I think 2 short rods mounted each side in line with the bottom of the top semi circle on the big window, with stationary drapery panels. They would sit partially over the 2 side sections.....then another pair hung at same height over the french door. They don't need to be too wide, just decorative.