Doubts when using a high pan toilet

Q: I use a raised toliet, when I use water to clean my private part, this water touches dirty water in the toliet then some dirty tiny drops of water bounce back to my legs so basically when I was wash my private part with water this water drop down and mix with dirty water then bounce back to me.  When I look carefully I see very tiny drops of water on my legs. Do I need to wash my legs with clean water? I was told by an Aalim that I don't need to wash my legs because they are only tiny drops of water.  I was told to ignore this but I worry my salah will not be valid.

Doubts with regards to ghusal

Q: I made ghusl and soaped my body twice then gargled and put water on my nose but something tells me I've missed places out although I soaped the whole body twice. Could it be possible for me to miss a place out if I soaped the whole body twice and will fard ghusl be done?

Tawbah

Q: A brother used to rape his own minor sister for many years. Later this same siter kills her brother, will she be accountable in the court of Allah?

Inheritance

Q: Deceased person has mother, wife and two children (son and daughter). How his belongings will be divided? At the moment grandmother of the children is 90 years old and lost her realisation and she has two brothers and one sister. Can grandchildren get grandmother's belonging (If yes) then how? Grandchildren are taking care of her grandmother because both her sons are deceased.