Three rules questions arose in a match today. First, since debris fields deal damage instead of cards, can a ship with a brace token available use said brace and reduce the damage by one? I rather expect not, but it would be nice. Second, if a damage card says to discard a defense token (don't remember what it's called and I didn't write it down), and later in the match the starship uses engineering to discard that damage card, does the defense token return? Third and final question, when using the objective Fleet Ambush, is the first player (the one setting up in the ambush zone) able to deploy squadrons near those ships, or only as normal in and near the deployment area? Thanks a lot guys.

Defense tokens are used at a specific time during the attack sequence. No attack sequence, no tokens.

I'm not familiar with the specific damage card, but I wouldn't expect to get the token back. On the other hand, I would have expected such a card to say "discard a token, then flip this card face down" does it not say that?

Squadrons have to deploy within a certain distance of a friendly ship. There are no other requirements unless the objective says otherwise.

Forgottenlore is correct on all points.

No attack = No defense tokens. This also applies to Mauler Mithel engaging a squadron with Scatter. No attack, no Defence.

The card is "Injured Crew", and it is indeed. "Choose and discard one of your defence tokens. Then flip this card facedown.
Its discarded, and it becomes Facedown. even if you repair it, there's no getting that token back.

Squadrons deploy within distance 2 of a friendly ship. That can be anywhere within distance 2 of a friendly ship, which even means outside of the deployment area in advance of those ships... But a ship must be deployed first, obviously.

Fleet Ambush solves the deploy ships first bit quite neatly. Thanks for the clarification guys, I must have overlooked the turn the card facedown line.