HMHM:

1) No idea, I usually run in a pre-made and our DPS is too high to see it

3) She "eats" the adds either at a timer (slow DPS) or when they're nearly dead (fast DPS); nothing you can do to prevent the AoEs, just minimize them. Add spawns are affected by boss HP

CBMHM:

1) Fire cast is determined by boss HP, but I also think it can be "forced" early by moving too far away from the boss.

2) Adds randomly aggro someone, and should just be killed ASAP. No tank-and-spank before bombs, you can only damage the golem with bombs. Anyone can do bombs, as long as they know when/where to place them.

3) Adds have no aggro meter; just have to kill them ASAP.