I love the purple, but I think your "word" on the wall says it all: SIMPLIFY! I'd leave the paint as is except I'd paint the door white to match trim. If you're going to do curtains, do pairs, not one panel per window. The biggest project is to unify and simplify the furniture. There is too much of it and it is a mash-up of stuff. Do you have access to something like IKEA? I think then entire dining end of the room needs some wall-to-wall built-ins to replace the desk, file cabinet, basket/bins and storage cabinet. The chest under the TV could be replaced with something lower and TV could be wall mounted on an articulated arm for flexibility when viewing from sofa or from the 'schoolroom.' Your long space does not need to be lengthened any more and the mirror at the sofa end is doing just that. Here are some IKEA units to inspire you. I'd also look for a long contemporary white table to replace the country cottage style one you have.