A comprehensive approach to design and implementation of the plans would benefit you in this case. A team of interior designer, contractor and possibly architect (if walls are moving or there is a more involved construction plan beyond decorating what is there and dealing with functional issues related to the interior design). Sequencing of trades and scheduling is the job of the contractor while providing costs for the implementation of design work. Designing and dreaming up solutions is the job of the architect and interior designer. Using a team approach with egos left at the door will give you a doable design, a solid budget and a reliable schedule. Best of luck with your project!

I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

Thanks a lot for your comment. I wouldn't exactly call it a walk in-closet. As you can see from the drawing, Its space provided for two single wardrobe (one on each side). Maximum width can be around 3.5 ft. The humidity point is quite relevant. The question is would it be possible to include a wet room in the space i.e. 6ft x 8.6ft. - considering I don't remove the dress wall. Wanted to get a sense on the possible layout. Thanks and look forward to your advise.

The usual approach would be to put the shower enclosure at the end with the window -- you could make it 48" by 40" so that it would feel spacious. Then the toilet goes on one of the long walls, facing forward. There's really no other choice, since you need something like 30" around a toilet, so it can't go next to the shower anywhere. Since you seem to have some kind of vestibule taking part of your 9 feet, you'll probably just be able to make all of this fit.