Photos will definitely help plus details of any furniture, flooring and rooms orientation. Have you looked at the pure collection? Quite calm and non-retro

There was probably a fireplace there that was removed. The idea is a vent helps to stop damp although opinion is divided about if this actually works. It will feel like there is a draft as this hole is big but if you put a grill on it the airflow will be reduced to a trickle. Search online for fireplace vents.

hey if you're thinking about pink on the other walls, maybe you could have 2 walls beside the featured wall painted pink and the 3rd wall a neutral light colour? I've added links below for you of the colours I've added also for you to have more of a look at and see what you think 🙂 https://www.lickhome.com/paint/pink-03 https://www.lickhome.com/paint/pink-01

I agree with the previous comment. The paper is lovely you just don’t have enough other colour or distraction in the room - so the paper is all you see. You have not co-ordinated the room enough so again the paper sits as odds with the bed and blind. Pink and green do go together but you haven’t reflected any green in the blinds. Bed Linen or in a throw. It would also be worth having a mirror on the papered was to bring some light into the room and bounce the co-ordinating colours into the wall - I swear by mirrors! You may also consider covering your headboard with a toning or contrasting colour. Headboards are not that difficult to cover and you could pick up a remnant or odd curtain which tones from many places - all you need is a staple gun :) You may have a number of doors in the room , which the picture doesn’t show, however a chair or an occasional piece of furniture or a plant stand with either a real fern or artificial fern may help. Best of luck and hope you love you bedroom very soon.