If Bellamy had cut such a thick big metal grill from four side with an Acetelyne torch, it would be so hot that his uncovered hands would have got burnt on grabbing it to throw it aside.
At the very end, when Murphy throws the rock at the solar panel, his throw is horizontal to the ground. In the next shot, the throw is more vertical so it can hit the panel.
When Jaha, Murphy, and crew discover the "City of Light," Murphy says, "Emori was right" but pronounces her name wrong. He says EM-ori instead of em-OR-i.