That's about as good as you're going to get, with DayZ. The grass they use has a unique ability to HOSE streams.
From what I saw, it looked quite good for what it is. You will never get a true 1:1 quality stream though; I'd advise coming to peace with that.
As far as what you can do, running at a slower preset (as you don't appear to be duplicating frames) may help. Trial-and-error there though, for the most part. Really, switching games will net you the biggest gains though.
Additionally, I'd recommend potentially dropping from 2750 to 2000kbps; as a non-partnered streamer, this is the recommended max... you can exceed it (up to the 'hard recommended limit' of 3500) but if your viewers start to go into buffering hell, you don't have the transcoding options available to allow them to switch to a lower bitrate view... and they may just switch to a different stream instead. This WILL increase pixellation under high motion, but generally the increase in potential viewers tends to be worth it. No one will come to your stream specifically for crystal-clear video... but they sure as hell will leave if they get stuck in a buffering-loop constantly.
I'd also consider switching to 44.1kHz audio from 48k... the extra bandwidth generally isn't needed, and 48k mode was mostly added for a select few devices that couldn't run 44.1 without weird issues.
Lack of a webcam is also notable (they're pretty much a de-facto requirement for livestreaming at this point), as well as a lack of any commentary on the sample video... but that's more of production concerns (and possibly just a result of a demonstration sample VOD) rather than nuts-and-bolts encoding settings.
