This is my favorite map to play Murly on. It's not the easist but the one I have the most fun on.
You defintely want to get bribe on this map and live on the bottom lane. Once you have two bribe stacks grab their bruiser camp. Pay attention to middle and clear that once in a while as well.
In a perfect world Murky would always get into the Dragon. But it's not something I obsess over. Even if I'm in middle lane I am more likely to chase the enemy to their tower as it is much better if I die than if my team mate dies.
If you do get the dragon attack the top or bottom lane forts instead of the midddle. It makes it easier for your team to cap a fort if the enemy can not escape to a safe fort and tap the healing well.