Miri Says Looting Starts Shooting Starts
 Arbites Build - Warhammer 40k: Darktide 

1. This is going to feel squishy compared to some of the melee builds when you don't have Castigator going. The axe is meant to let you kite around waiting for the chance to do that again but if you need a Suppression Shield with Block Efficiency as an alternative that's an option. Whenever Castigator is up you should feel fine. Don't be afraid to turtle with your dog while you let Man and Cyber Mastiff get you back to full, and rely on blocking, pushing and dodging to buy time for Castigator even when playing with the Taxe. 

2. This is very gun-oriented. I think either the Combat or Exaction Shotguns are best for this, but I've used this with basically every form of Arbite legal gun, though I take up Soulguilt Scan when I use a more heavily marksmanship coded one like the Vigilant. While I do think a Surgical + Deadly Accurate Blessed Bolt Pistol is an option here my favorite choices on the Bolt Pistol continue to be stuff that uses Arbite Grenades with Lethal Proximity Blessing instead. Arbite actually has so much access to on demand Rending from No Lenience and Prosecution Blow, Brittleness from Serrated Maw, Weak Spot damage from Soulguilt Scan and Crit Damage from Efficient Killer that at that point I actually would rather use the Vigilant autogun as a marksman weapon basically every time. Note most of those aren't taken in this build; you basically wind up dropping Blessed Armament for Efficient Killer and Priority Endowment for Soulguilt Scan to get the aforementioned Crit & Weakspot damage, while dropping Judicious Efficiency's reload speed for No Lenience's Rending. The net result is a move away from raw volume of shots and towards fewer shots that emphasize crits and rending, but the Bolter works fantastically in both ROF and precision oriented configurations of this Talent tree.

3.  Arbite as a pure ranged experience is, IMO, infuriatingly, one of the best in the game and only held in check by the fact it absolutely chugs ammo. Be mindful of that. Very easy for it to be a sugar rush where it does wild damage but the show's over if you're not finding ammo or are being bad in your shooting.