From the stem

b={...-4, -2, 0, 2, 4...}

Question

is b = -2 or -4 or -6...

Attack statement 2 first because, off the bat it seems like it would not work
(2)

b^2 > 9

b=...-6 or -4 or 4 or 6...

Since we get both positives and negatives in our set, INSUFFICIENT

(1)
b^2 - 4b + 4 < 16
b^2 - 4b + -12 < 0
(b - 6)(b + 2) < 0

Since we must have a positive multiplied by a negative to get a value less than zero, one of b-6 or b+2 must be less than zero

If b>6, both parenthetical expressions are positive. If b < -2, both parenthetical expressions are negative. So we must have -2 < b < 6. But note that leaves us with the set b= {0, 2, 4} which is always positive or 0. Therefore the answer to the target question is no and this is SUFFICIENT.

That was kind of a tough one. There may be a more straightforward approach...