Re. infrastructure integration: it's always a cost-benefit analysis. I've worked at a robotics company where we integrated with doors and elevators. Doors was really easy, cost almost nothing, and didn't come with any regulations. Elevators, on the other hand, was a length process, required certified elevator technicians, and cost a lot of money. On the other hand, adding a manipulator to open manual doors is very difficult and costly (per robot), but adding a button-pusher for elevator buttons is not.