If I understand the seasons in India correctly, you have already been through the rainy season. Don't wait until the next rainy season to get the problem with your drainage fixed. Now will probably be the ideal time to get it fixed. Please get someone who will tell you what to do and then have the work done. The paint on that wall in your beautiful home will keep coming off!

Get an achitect before you even start this project just because you havemasonary walls does not mean you can add a second storey.

Going with professional has its own advantages. Afterall he is pro, so he has studied more and has more experience. However is this person from the kitchen shoppee, which is giving you quotation of kitchen installation? In such cases, I have experienced that they just make boxy kitchens where they add lotsa fittings, that increases your budget. Open shelves does not need such fittings, so such are omitted...Normal door wali cabinets are less and number of drawers increased. Going on own is not a bad idea, provided you need to study it well. Note down the requirements, classify work areas and so on... In this approach , you have to go bit slower and carefully. Allow some flexibility in design, so that in future , you can alter as per the need. Sometimes we come to know the problems after few months/ years and we cant change it later. Ultimately compare between [your time+ efforts+ study+ error chances] Vs Hiring professional and go ahead accordingly.

The wallpaper colour and print is rather strong and overwhelming. So I suggest you keep the rest of the room predominantly white. White walls, white open shelves on the wallpapered wall, white roman blinds with a peach border to match the wallpaper. Night stand, bedside lamps, soft furnishings all white. You can have a single seater armchair, in pale beige or cream with peach piping, and peach and white throw cushions, which you can repeat on the bed