ownership

Adding the condition "goods belong to the seller until paid for" in a sale

Q: Please advise on below:

1. Many companies state at the bottom of their invoice "goods remain the property of the above company until fully paid for" What is the status of the goods?

2. Is it amaanat or does ownership pass on to the purchaser? Is such a condition permissible?

3. Will the sale be faasid if such a condition is added?

Inheritance

Q: A person passes away with three sons who inherit 33.33% each. Does this mean that they get ownership of 33.33% of each item? Or does it mean that they get full ownership of 1/3 of the items? If so, how is it decided which son gets which item?

Inheritance

Q: I have a question regarding inheritance. If someone could please kindly answer. I would be most grateful. A father has 5 children, 3 sons and 2 daughters. His house is in his ownership. he makes a verbal arrangement amongst some family members that this house belongs to one of his sons, although by law he does not transfer the ownership of the house to that son during his lifetime. The mother insists that even though the father is still alive , the son to whom the house is promised after the fathers death must pay his younger brother his share of the value of the house. Regarding the 3rd remaining brother it is verbally decided that he will not receive any share of the value of the house as his parents have already financially helped him. Furthermore it is agreed that the two daughters will not inherit and they both verbally express they forgo their right of any inheritance in favour of two of their brothers. If you could please give me the Islamic ruling on the validity of all this.