If $A$ and $B$ are both $3 \times 3$ matrices, then which of the following statements are true?

(i) $A B=0 \Rightarrow A=0$ or $B=0$

(ii) $A B=I_3 \Rightarrow A^{-1}=B$

(iii) $(A-B)^2=A^2-2 A B+B^2$

$A=\left[\begin{array}{ccc}1 & -1 & 2 \\ -2 & 3 & -3\end{array}\right]$ is the given matrix and $A^T$ represents the transpose of $A$, then $A A^T-A-A^T=$

If $A=\left[\begin{array}{ccc}x & 2 & 1 \\ -2 & y & 0 \\ 2 & 0 & -1\end{array}\right], x$ and $y$ are non-zero numbers, trace of $A=0$ and determinant of $A=-6$, then the minor of the elements 1 of $A$ is

If $i=\sqrt{-1}$, then $\sum\limits_{n=2}^{30} i^n+\sum\limits_{n=30}^{65} i^{n+3}=$