Here’s my meta Veteran build that ticks all the boxes you’re looking for. It’s a great all-rounder with lots of ranged damage potential, tears up elites like nobody’s business, shuts down gunners easy, and you really get to FEEL like a guardsman with your trusty hittin’ spoon by your side.
Compared to @Molonious’s build, i think Shredder Frags are overall better, as the crowd control they provide is invaluable, and you’ll be able to handle heavily armored targets fine with your Columnus in hand. I also think Catch a Breath is superior to Get Back in the Fight!, as it provides a means of passive Toughness regen when solo, and helps with the occasional stray bullet.
If you’d like to use the plasma gun instead, drop Onslaught for the crit chance node to the right of Toughness DR above Voice of Command. 5% is A LOT. Keep Their Heads Down! helps with Gunner suppression a lot, it can give your team some much-needed breathing room.
If you want to use a different single-fire weapon instead (like the ADS revolver), you should take Deadshot instead of that 5% crit chance node. There’s no reason to ever alt-fire the plasma gun, but ADS with the revolver should be muscle memory. I’d also recommend dropping Duck and Dive for the Target Down! addon for FT, and the stamina regen delay can still be taken next to Superiority Complex. I’d also swap out a Toughness curio for another Stamina curio - maybe even both Toughness curios. Stamina is super duper important, especially when one of your talents is draining it!
I don’t really like the temporary bonuses you get from popping active ability - they last too short for me to enjoy, especially For the Emperor!, and I’ve found I don’t really need them.