you can go for vitrified Italian tiles

Can you upload a picture? Do you have a copy of the existing plan? If not can you roughly sketch a plan out with measurements of existing rooms, doors and windows?

Your terrazzo flooring is one of the most durable floors but they need to be cleaned and sealed with a clear penetrating sealer to enhance their appearance and to prevent wear and tear. This is a hairline crack, simply sand the area with 80 grit paper, fill the crack with white portland cement, let dry, sand again with 200 grit paper, once satisfied apply concrete sealer.

Thanks for both of your responses CUBSpaces team and Shweta from Shades studio. It really gives a clarity about possible consequences. I am now doubt free about changing whole things in Bathroom as it will be interconnected. However will appreciate your opinion on few things: 1. Kitchen wall tiles: I have those from countertop height to roof(almost area of 6X15 feet) which are good and not hollow. I changed countertop 5 years back without any damage to these tiles. It might cost me another 10-15 K, but I feel the whole process and quantity of wasting old good tiles makes me little sad. 2. kitchen countertop: Made new around 5 years back. I don't expect to get it all intact. But large pieces can be cut and can be used as top for other freestanding structures like dishwasher, front load washer, heighten base cabinets, etc. 3. Plywood: I don't mind giving enough labour charges for old sheets recycle. I am planning to use doors, loose sheets(like kept on bed frame of settee frame.) or parts of big frames like settee. I am keen on reducing waste than to save money. You can see various DIY ideas by western people, who remove or sand laminates and re-paint furniture, or carefully remove hollow tiles and re-attach them. Some are also re-painting ceramic tiles. I am just asking myself: Are we creating more and more waste by use and throw approach every 10-15 years, just because we can afford it?