Don't chat. People get defensive and feel like you are attacking them when you offer them suggestions. You can only control what you do. If you feel like you are responsible for more than that then you end up placing unnecessary stress upon yourself that can hamper your game play. Use your instincts as a guiding force for your actions. Stay aware of your surroundings and of the enemy's positioning. Focus objectives over kills and do not engage when you know it is a bad idea regardless of what your allies say or do.
Bronze is a division of highly aggressive players who want to win through killing the enemy repeatedly. Games are often determined by whichever team ended up allowing themselves to die the most. Invasions, for instance, occur regularly because they want that almost worthless pre-spawn first blood gold (it's only 400 gold and it doesn't even net the killer much exp).
You can often drive your opponents crazy and tilting them by refusing to die altogether and only engaging for a 100% ensured kill.
Bronze is also a clutter of players who cannot coordinate well. Players will blindly pursue objectives on their own, making them easy targets. Find the easiest straggler and kill them then move onto the next easiest if you want to eliminate enough enemies to pursue objectives safely. It's how I got out of bronze. By assassinating all the tunnel vision cowboys I encountered in bronze.