I roleplay on the front all the time. Obviously when Xenos are breaching and you're running for your life you can't roleplay, but there's no reason you can't backup a screen while there's a clusterfuck going on at the frontline and roleplay. There's almost always marines milling behind the front healing up or building foritifcations. What's gonna happen, a runner will naruto run around a bit and spook you by hitting you once with their claw and running away?