Does the ruling on isbal mentioned in the hadith: "Whatever is below the ankles of the izar is in the Fire" apply to jeans, and does the ruling differ if socks or high-heeled shoes cover the ankles?

There is no relation between isbal (letting the garment hang below the ankles) and socks or sandals. Rather, it specifically concerns what covers below the two ankles of the izar (lower garment), and it includes all garments such as the qamis (shirt/tunic) and trousers. The isbal that is forbidden is that which is done out of arrogance. However, if it is not done out of arrogance, then it is a point of disagreement among scholars.