2. Teamwork
Why it's broken: The whole of Battlefield revolves around team work. So many times was I left hitting Q over and over to try to get a team mate to drop ammo or health, only to have me die because either ran out. There is no real reward other than points for helping team mates, the game never indicates for you to do so.
How to fix it: This one is a bit complicated. Firstly, you can never force people to work together. But to combat this, BF3 offers people point bonuses as incentive to help out. While this is a sound strategy, DICE needs to implement some way of making you feel weaker when soloing it. The squad specialisations are a good start, but maybe giving people more points for working together to cap objectives, like in Mass Effect 3, would help. A basic move up or fall back command system in CommoRose would help, and commands need to be much louder and more obvious. Also, if I request ammo from a team mate, the game needs to flash an icon on my head or something to indicate that I need help. A few extra additions would go so far. Taking out regenerative health would be a nice touch, too.