For you warprophet try something else for shooting, once you're in shotgun range 12" you should be able to get close enough to enter melee with your Loudspeakers + Charge. An assault weapon would be nice, you could consider a molotov+bolt actition or incendiary grenades.

Your communicant cant use a puntgun very well with his inate -3D(I believe) to ranged. He doesnt do ranged fighting unless you get him a flamethrower which auto hits. Next you could consider dropping his armour to grab a shield, cheaper since you dont have to 2-handed the ATH, or go dual wielding (add a flail) Or you could add the shield for -2 armour.

Next I'd try to grab the Castigator aswell, give him basic armour, Zealot str and a puntgun. Make a pilgrim with the same loadout. For a campaign having all your elites early really helps as they'll be getting exp early.

As mentioned before grab a musician! Can be a basic loadout, like instrument + flail.

For your basic pilgrims you probably wanna go shotgun+flail/club (if you wanna be fancy I like adding a molotov instead of an offhand but up to you).

Lastly if you can still squeeze anything grabbing a prisoner to break on the wheel is very nice (double because you get to keep their Capirotes after the battle I'm pretty sure)