Skye has the highest DPS in the game when at close quarters. Sometimes it's better to turn around and block her shots with your shield or Charge away. Judge from where the most damage is coming from.
Save your Fireball when Seris is healing her tank. Combining that with Cauterize on your flamethrower, your tank will get healed less, so he will require more healing attention, as such, reducing the survivability of their tank and other teammates.
Salvo does insane damage to your shield. Wait for Drogoz to use his Salvo before pulling it out. If his team is not focusing you, you might save your shield if they decide to push.