In your opinion, are civilians still non combatants if they attack soldiers with bricks or petrol bombs?

No. They are definitely combatants. I think the human mind is the weapon, not the gear they carry. I also think any soldier, gangster or cop knows that. But the soldier is taught to follow the rules of war and when i comes down to decision making they are really just political pawns sent in to complete a task for someone higher up. Not every soldier wants to go to war just cause they like killing and destruction. They are taught to believe they are defending those they love by killing who ever they are told is an enemy when really we are just all the same humans in the same boat killing and destroying because someone with power told us its right.