As recommended by a professional painter: to paint over any surface, without sanding, use a product called 'ESP: Easy Surface Prep' available at hardware and paint shops. Wipe on, wipe off and paint in 90 minutes. Saves hours of work!
No Sew Faux Roman Shade -that can actually move and drop to the length of the window! Maybe do a faux roman shade over the blinds (to cover them when up) and a valance over the window insert with coordinating fabric
When a soffit can not be removed because it is hiding duct work, plumbing, etc. for the house, covering it with matching cabinet material allows the cabinets to flow to the ceiling. The optical illusion of taller cabinets makes the ceiling appear higher.