It would seem that Batman was there even before Joker was put in the room.
Yeah, but if that's the case, how did he have a discussion with Gordan beforehand?! Because the MCU had been interrogating Joker before Gordan arrived, so how could Batman get in there before the MCU, Joker AND still talk to Gordan? And if he was there beforehand, we didn't he rough up Joker until after Gordan showed up?
Did you miss the cut to Gordon rushing to the door to open it before Batman barricaded it? And then when he got to the door and couldn't budge it?
No, you misunderstood me. There are two doors in the room; one in front of Joker - which Batman blocks off - and one behind him. So I was saying why didn't they attempt to get in the room from that door?
Gordon apparently planned it out the little trick with Batman beforehand.
This is what I assumed, but again, how did Batman sneak in the room without anyone hearing it?
When he got Lau to tell him the location, the mob guys allowed him his own share.
Obviously he got Lau to tell him where the location was (and he shared it with Maroni/Cechen) but did the 'deal' between Joker and the mob change? Originally it's set up as he'll kill Batman, but he doesn't. Does it somehow change to 'Get Lau and our money back for us?'
Although, since it wasn't split amongst anyone yet, he ended up burning the mob's entire funds. "I'm only burning my half." is funny because of this.