Amboseli, Thank you for your question. This towel hook cannot be installed inside of the shower as it has not been tested for constant contact with water. Best, Customer Care Team
Yes, it is open in the back whre it attaches to the mounting bracket.
Yes, but you may want to trade out the screws with stainless steel #6 1-1/2" long. Use the right drill is mounting to ceramic tile. Mounting height 65-70 inches.
I would assume so provided the door is solid. If it was a hollow core, I would not.
2 3/4 inches
The base is a 2" x 2" square. The distance from the wall to the outside of the hook is 2 3/4 inches.