1. It's always better to inform the hotel about your vacant icon via booking a room. Better be safe than sorry while you try to find NOT booked room in a popular hotel.
2. To book a room you should contact hotel's manager, do ask they say and then proceed to give them your contact information in case of emergency on their side.
3. Usually an assistant comes to take the luggage, but if there's not feel free to ask for one or, if the staff is ignorant/rude you may take the luggage into your room and then report the staff.
4. Receptionist, they know almost everything.
5. Passports, face scans, documents made in the touris bureau.
6. Не знаю.
7. Usually they are given some instructions about how to find their room. But I do belive that sometimes there's a sort of an assistant.
8. Because it's as important as booking ahead, receptionst would be ready in case of some unfortunate situations and just in general, they can't sign you out in 1 hour.