I wrote a piece about teamplay/general strategies to make use of in case anyone is interested:
http://harshbandito.tumblr.com/post/146830554713/how-to-bring-pro-strategy-to-your-pub-matches
To sum it up, hold at positions which are favorable. Team fights are called team fights for a reason, so don't charge in as Reinhardt or w/e just cos reasons. Basically don't overextend.
re pluff, isn't Aus located for the Americas login region, as is SEA etc? You should be able to get AUS or SEA servers rightfully. But then again people have been saying Aus servers are weird so idk. From my own observation, your MMR at low levels is incredibly volatile. So you might be getting matched with players all over the place in skill :c It'll get better as you play more I think.
re Zen. Yea Zen is in a pretty bad position, simply because HP and no evasive skills making him outright worse than Lucio and Mercy at pure support. I like Zen though cos I like multitasking and killing while healing. I'm an aggressive Medic main in TF2 and I trust myself more to defend myself than teammates, which can be done with Zen. Except that 150 HP means you die to a sneeze so you have to kill your enemy in literally 1-2s before they sneeze on you. It can be done depending on the disparity of skill levels.
Also ranked is really horrible. I duo queued with my friend and we literally carried the team all the games. And yet, teammates leave the game even after we held the first point all the way, and also leave when we aren't even actually losing ? Seriously, getting penalized so much for people leaving is dumb. The game should just not register the stats of the game for you if your teammate leave, and count it as a win for the opponent. Unless the leaver is on your group party, then penalize the party with a loss if no rejoin is made. I'm tired unnecessary penalties when you already outdid literally both teams by a fair margin. Not saying we were a pro or anything but it's obvious both the enemy and teammates were below our skill level when you see basic mistakes like feeding happening so frequently. (Also getting gold elims as Zen while lagging throughout the whole match lols).
All these penalties are ZZZ and it doesn't reward you for doing well.
Also ranked 50 plus is a joke. The variance on the distribution on ranks simply isn't big enough. 50s is just full of people who are skilled and unskilled and yet still hasn't been able to sort players appropriately yet.