To simplify this expression, we first need to follow the order of operations:

3^(-3) 3^5 / 3^3 + (3^(-1))^2 - (3^2 / 3^3)^2
= 1/3^3 3^5 / 3^3 + 3^-2 - (3^2 / 3^3)^2
= 1/3^3 3^5 / 3^3 + 3^-2 - (1)^2
= 1/3^3 3^2 + 3^-2 - 1
= 1/27 * 9 + 1/9 - 1
= 1/3 + 1/9 - 1
= 3/9 + 1/9 - 9/9
= (3 + 1 - 9)/9
= -5/9

Therefore, the simplified expression is -5/9.