Guild Wars 2

Hello, I am a returning Engineer (not returning to the game, just returning to the profession after about 2 years of not playing it. Freshly leveled one to 80) and have a few questions about build.

I put this one together with WvW roaming/zerging in mind.

What runes would be best? I’m stuck between a few of them; Fire, Traveler, Berserker, Flame Legion.

Would it be better to go full Celestial, is the current mix okay or should I maybe make my Rifle also Celestial?

What would be a better choice in place of Doom and Bloodlust sigils? I’d like to keep a stacking sigil such as Corruption, Cruelty or Perception, though.

Recommended utility food? I prefer to keep Saffron Bread but I’m unsure if Oil is best for Utility.

Any advice on traits/utilities? I want to keep Inventions and Firearms because I really enjoy Energy Amplifier and Incendiary Powder.

Disclaimer: I am not looking for a min/max or absolute top tier build. Just a versatile one that can do respectable damage but has enough sustain to get some extra use out of Healing Turret. I feel that the one I’ve made is decent but advice is always welcome since I’m not extremely familiar with Engi although it does click with me very well! So being on the squishy side is acceptable (: