I'm sorry to hear you've lost your father. Please accept my condolences.
To your questions:
I don't know if this particular monk can see or hear your father. Some Buddhist masters are said to have this kind of ability, but it is rare.
I don't know for sure what that particular series of syllabus may be, but I think it is a Chinese way to practice reciting the name of Amitabha Buddha. This is a form of Buddhism called Pure Land. You can find out more about it here on Dharma Wheel if you are interested.
Honestly, this sounds like a weird situation for a son to be in, like maybe something is lost in translation or ????, so I don't blame you at all for feeling skeptical. I think I would too if I were in your shoes.
Do you know the name of the monk or what temple he belongs to? That would help sort out what's going on and maybe bring some clarification for you and for your mom.
Hang in there.
Great River Tendai Sangha: a Tendai Buddhist community in Alexandria, Virginia, USA (near Washington, DC):