MB4 251b: Acquiring Rights to a Chatzeir from a Gentile’s Wife or Workers (382:11-14)

Rights to a chatzer can be acquired from a worker or wife of the owner for an eruv chatzerot, even against the owner's wishes.

From what kind of workers can the rights be acquired?

If a Jew has reshut to store an item in the gentile's property is it still necessary to acquire rights from the gentile? What if he only gave him rights to use a specific part of the house?