shaving blades women

Salaams I would like to know is it permissible for lady to use shaving blades on her body or must a lady use the hair removal cream that is sold instore.
I would like to know if a man can share the same bed with his wife when she has her monthly period.
I would like to know if a non-muslim can engage in ( muslim) her families wedding meaning touching niaz food that is being prepared for the host and I would like to know can we do Mehendhi because people say its not permissible.