I think that you need mostly white, but something in a print that incorporates your colors. Perhaps pillow slips or at least a mostly pea green painting/poster/wall-hanging that also has some brown, perhaps in the frame. You could also do a stencil on the pink wall using the green paint, some white, and some brown. How about a nice tree branch? You can also buy vinyl decals from Etsy or other places--not sure that you could get pea green, but brown and white should be available.

You will have to probably redo the shelves completely. Looking at how they are built you cannot just remove the middle to put the TV in. You may be able to put some support under the shelf that will be just above the TV....just consider this. I would paint the inside of the shelves a fun color- cobalt blue or burnt orange maybe. This will give you a great backdrop for your things and keep the TV from becoming a black box on the wall. It's a great space!

Sorry but I don't understand your pictures. You are talking about 2 bathrooms but we see only one floor plan. Is the 1.52M x 2.24M the 5 x 8 bathroom in your dilemma title. If so, can we see the floor plan of the 5 x 9 bathroom? Is the space with a small rectangle in the middle the extra 5.5 x 4.9 ft space you mentioned in your dilemma? Also 1.52M x 2.24M is in reality 5'0" x 7'4". This is 8 in. less. It can make a big difference on how to place fixtures in a bathroom.

Definitely bring the tapestry down closer to the sofa. If you are keeping that above the sofa, your rug should be less busy. pick a color from it and use that on your rug. You've got a lot of pretty patterns in that room already, keep the rug less busy.