MB4 235b: Dwellers in Apartments and Hotels Obligating Towards an Eruv (370:2-3 - part 1)

If one person owns several apartments in a chatzer and rents them out, who is obligated to contribute to the eruv chatzerot? What if the landlord is a נכרי or מומר?

The landlord has a תפיסת יד if he owns a large, heavy object that remains in the apartment.

Making an eruv in a hotel room: does the hotel owner have a תפיסת יד?

One who rents from a non-Jew and rents out part of the rental to another Jewish person.

People living in a large room that is subdivided: if everyone have to go through one person's area to exit/entrance.