I think, it is easirr to plan, if you use excel to draw the rooms to scale. I use 1 grid box to reporesent 1 foot. Then measure the furniture u need and use excel shapes to represent the fittings to test out.

If space is short, ceiling fan is better than stand fan. KDK baby fan is very good for low ceiling, and quite windy. Wall to wall cabinets can give u maximum storage. Instead of putting a low cabinet beside a bed, can consider some build in cabinet cum headboard for the bed...

For room A, if u swap the computer table n wardrobe, maybe u can get more wardrobe space.

Maybe costly, but sometimes, moving a door can help you layout your furniture better. So think about that too..