I got my marine to shoot his Gauss Rifle and Marauder's 'nades at the same time by adding the wanted weapons to my Marine (Data Editor -> Marine -> Combat - Weapons). After that I went to edit the Marine's Gauss Rifle (Weapons tab -> Marine - C-14 Gauss Rifle -> Weapon - Options, and unticked "Linked Cooldown").
If there are any better ways, someone should post 'em here or make a tutorial. Hope this helped!
I don't think I'm dealing with quite the same pressures though, at the very least its a significantly smaller system. For the time being I'm just going to put together a quick scrubby box though and hope it works good enough to not make my house toxic
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.