If I play Wild Attack and Element of Suprise when I declare my attack, can I use Element of Surprise to remove the white die granted by Wild Attack?

Yes, if the condition of Element of Surprise is fulfilled.

"Wild Element of Surprise Attack!!!!"

Dude. Focused HK's with Wild Attack. Played this against a Repulsor Tank the other day. 10 squares away, did nine damage with the first HK using focus and Wild Attack, after defense resolved. Nine Damage, 10 squares away. The other player flipped, and honestly, I did, too. Couldn't believe how punishing it was. I did have to use the second HK to finish off the tank, but that first snipe was incredible.

Snipe, ha. More like a missile.

ESPECIALLY for zero points, its an AMAZING card for any figure that can strip dodges. HK's can reroll defense, so it's awesome. Also great on the Inquisitor, as he can spend a surge to clear a dodge.