What is the ruling on an insurance policy with the aforementioned features (a quarter of the amount at two-thirds of the term, half of it at its end, and the full amount upon death, along with participation in profits), if the intention of the questioner is saving, not interest?

Commercial life insurance is a commutative contract based on ambiguity (gharar) and gambling, thus it is impermissible to voluntarily participate in it. This differs from cooperative (takaful) insurance, which is permissible to participate in, as it is based on cooperation and risk diversification, and does not aim for profit. The amount paid by the participant in it is considered a donation.