Can I port blink over and destroy a square of blocking then port back? Since when destroying a square of blocking terrain "the attack automaticall succeeds".

I would think yes...?

always quote the thing in question

Please remember to quote the power in question... You will get a quicker response:

BLINK AND YOU'LL MISS ME: Give Blink a power action when she has no action tokens. Place her into any square within 8 squares and make a close combat attack. If she hits you may return her to the square she occupied when the action began.

On her first and second clicks she has 3 damage so I imagine this will work.

Even when she has a 2 damage value, the attack still hits, it just doesn't destroy the terrain.