Hey Sudha ji , I'v a few ideas on the placement , a bed takes 9'x6'3'' so place it on the 15' Wall(you can reduce the width by removing side drawers,then you get 3' extra for bigger wardrobes on both sides) with one wardrobe on each side one for him and one for yourself and a chest of Drawers to keep other stuff handy and two Ottomans or love seat in front of the bed so you have enough space in front of the bed for traffic as well,and on the front wall to the bed place your Wall hung T.V, PLEASE keep the colours light , use white marsh by Asian Paints or Honey dew , here are some pics .

If you can't clean up the painted edge, you could always add a 1x3 piece of wood as molding. You can even carry it up to the ceiling to frame that wallpaper. I don't see that paint color in the wallpaper, or maybe it's a lighter version of the flower centers. Maybe stencil on a design using the darker color, or another color from the wallpaper to help tie it together. Then narrow floating shelves or vertical frames or something in the painted areas it you feel you need it. Maybe turn the bed around so the wallpaper is the headboard.

I think you can start by de cluttering. There's too much going on. If you want to keep the bedspread, I would pull some colors from that. :) Teals, browns, whites. It would make a pretty room.

the design looks great . According to me one side of windows can be used as bed wall . we can have blackout curtains or blackout window blinds . You can even play with drapery to define the area behind bed. We already have seating in the room so next we can do is give a console/ study table with an puffe / chair to it. also one can add a bench at the end of bed. Size you can check on your Autocad . Bed wall should be the focus when one enters the room, so I feel the bed should be placed like this . Dimensions of furniture and circulation space you can work on. Also WC should be on the washbasin side to avoid Future leakages and dampness in bedroom wall. all the best