According to Carnival deck plans, the room you were in sleeps 4 people. ‚ 2 uppers and 2 lowers, so I don't see how it only slept 3. ‚ Secondly, You are not supposed to sit on the stairs because it IS a safety hazard. ‚ This applies not only to ships but ANY public place. ‚  I think the issues that you experienced on the ship are NOT the cause of the staff or crew but the to the actions of said passengers. ‚