Was just wondering if the two works together or not? Because last night in the tourney,one of my main problems was a Rook Midnite healing Silver Centurion Ironman and Graviton almost back to full n hardly missing wheres hes in hindering and has the +2atk with ambush thanks in advance.

No. While Support is an attack roll it is not an attack. Ambush states that the bonus is given when making a close combat attack.

Nope. The defense and attack numbers remain unmodified.

"ignore all combat modifiers for purposes of this attack"

And what Hair10 said...