"I can obviously not imagine life as a black person in America" you could have stopped there on that matter, being that you are white and in the UK.

Lots of groups are trying to fan the flames...there have been no other flames to fan.

If black men had showed up with automatic weapons they would have been arrested, you cannot own and automatic weapon here...tell the rest of the world, who seems to be very unclear about the gun laws here, that none of the weapons they see Americans walking around with are automatic weapons. In answer to the main point of your question, I think they should have showed up armed right from the start. A show of equal force tends to keep the other side from doing anything aggressive...like firing tears gas into crowds of people.