Have you had any other symptoms with your feet prior to the shower or bath? Do they get very cold or turn whitish or bluish? If so, you may have what is called Reynaud's Disease (not actually a disease). It is a condition where the tiny capillaries in the extremities overreact to the temperature around them or to stress. They will constrict causing them to become very cold and even numb and discolor. Thus, when warmed in the bath, they dilate and let more blood flow and become very red. I know the glowing red you are talking about. I thought everyone experienced it until after I was married and my inlaws were commenting on my feet after a shower. Look it up, and see if you experience the symptoms. It is mostly something annoying and not serious.
pumice. take a shower or a bath and pumice them. it helps.
Gravity. The shower head is probably 4 or 5 feet higher than the bath tap.
Yes, 90 sq ft is enough for a full master bath - with separate shower and bath. It won't be huge, but certainly sufficient.
They probably smell like everyone else's-- when people are busy or they walk a lot, their feet will perspire. But after a shower or bath, their feet will probably smell very pleasant.
Yes, it is called the Conair Thermal Spa Full Body Massaging Bath Mat.
Ogden Nash, a great US poet, wrote "Here in the bath I sit my mind is full of wonderment what chilled the finger not a bit is so cold on the fundament. " . The bottom of the bath/shower was at the temperature of the water. And the floor really is colder. Unless you live in the tropics.
At least six feet away. The idea is that you cannot be standing in water when you operate it. Most people can't reach 6 feet.
A good way to cure or deal with Ablutophobia is to find a way to relax before bathing. Or start slow with just dipping the feet in the bath. Taking a shower with the shower head pointed toward a wall instead of the body is good too.
A short shower saves water and is more healthy, as you have clean water running over you. Sometimes a bath is useful, for example, after a hard run, your feet might be sore, and a bath can help them relax.
Peeing in the shower has no health benefits for feet or any other part of the body. Peeing in the shower will not hurt a person in any way.
Bath mats
The bathtub was 7 feet long and 3.5 feet wide. The tub was used for William to bath in.