Janaazah

Can a Muslim inherit from a Kaafir and attend the funeral procession?

Q: A certain persons granny is non muslim and is on her death bed. She would like to know:

  1. Can she and her family attend the funreal / service if it is held at a church?
  2. Can they attend the function held after the burial which would be at a church? (From what I understand it is a meal with the family)
  3. Can her mum accept and use inheritance from her non muslim mum?
  4. Also a muslim sister says that she has reseacrhed that niqaab is not fardh for hanafis. Could I please have some information proving that it is fardh?