Is it permissible for a student on scholarship abroad to call his Christian landlady "mother" out of respect for her, and is it permissible for him to accept a foreign title from his teacher?

It is not permissible to address a disbelieving woman with the word "Ummī" (my mother), as it implies glorification and honor, and the Sharia has forbidden addressing a hypocrite as "Sayyid" (master). This is further supported by the impermissibility of addressing a disbeliever by their kunya (agnomen) unless they are not known by any other name, because the kunya is for honor. It is permissible to address her by her given name or her kunya if she is not known by any other name. As for adopting a non-Arabic title, it is permissible if it does not contain any Sharia-prohibited elements, but it is preferable to adopt Arabic titles.