conditions are both shower area and bath tub are required in the bathroom.

You might consider also the space a round table has compared to a rectangular one. Usually, the round table of a 5 ft. diameter will not have a lot of room for 6 people to sit. It will be a little snug. Serving dishes will need to fit on the center of the table or off of the table. The rectangular table would offer more spacious seating for 6. Is it too large for your room? What are the dimensions of your dining room? (x ft. by y ft) As to your color palette, the contrast of black with other white furniture is interesting. Also, the green with the black and white could be quite unifying.

Change the pipes which material won't get rusty and corrosion, plastic or PVC is suitable. I think concealed rain shower system is more perfect for your bathroom. Check the link and choose the ideal set: http://www.homary.com/shower-faucets-shower-systems_c157

If the shower area is sufficiently big, I would prefer to opt for glass partition as that ensures that outside dry area does not get wet, which may happen in case of shower curtain. Having said that, I would opt for shower curtain if the shower area is small to avoid accidentally banging my elbow against the glass partition while taking shower and getting hurt.