I have my fans at full blast when playing and that seems to help quite a bit. Also, I would advise that you get some sort of fan control software, mbp hates to be hot lol. So far boot camping seems to be the best option. I have tried using virtual machines such as parallels and VM but the performance was just as bad as the native mac client. I am able to wvw with minimal lag spikes on queued servers. This allows the game to be playable with a minimal amount of hiccups. Currently, the only way I am able to play the game is by boot camping into windows and playing on the 'Best Performance' settings.

I have experienced the same issues and have tried numerous in-game graphic settings combinations. Pretty late to the conversation but was checking to see if you had any progress.