no it is not appropriate as any one can see from outside and during winter you will be having bath with warm water and cool breeze will flow in from the window. if you want you can install bath tub next to the window as long as you completely seal the window
Yes, but for privacy you may want to install glass block as opposed to a normal sash window. The glass block will also prevent any kind of water issues from both inside and out. You can add a vent into the glass block to help air out the bathroom.
yes its okay. But the water droplets can go out of the window. When you use shower try to close your window. When you fix the shower near window the water can go out. If you use less amount of water there will be no problem. But if you turn the shower fully it may reach outside
It is good to have a shower next to the window, to let the steam from the hot water from making moss grow on your walls due to the humidity. However, make sure it does not show anything while you shower.