Is it permissible for the questioner to take ownership of the money, phone, car, and plot of land left by his uncle after his death, knowing that his uncle officially transferred most of his properties to him before his death, and intended for the rest of his possessions to be his, and that his uncle's wife does not object to this?

It is not permissible to take property (money, phone, car, land) after the death of the uncle, even if he intended to give it to you. Rather, it must be divided among his legal heirs. His statement, "everything he owns is yours," holds no weight as long as you did not receive it during his lifetime and he did not gift it to you while he was in good health. A claim of a will is not accepted unless there is legal proof. The testimony of the mother is not accepted, as kinship is one of the impediments to testimony. Even if a will is proven with evidence, there is no will for an heir. For a non-heir, it is valid only up to one-third of the estate. The transfer of property before death is subject to his health condition at the time of transfer and whether it was received during his lifetime.