When the Phantom is skidding off the landing platform after crashing, Hera slows their motion by pulling back on the control stick. Pulling back on a control stick causes a flying craft to rise upwards, not slow down. And in any event, the action was moot, as the Phantom had been struck by lightning and none of its systems, including steering or velocity control, should have been working, yet somehow Hera pulling back on the stick worked.
During the initial run on the blockade, Hera is in the pilot seat, moving the steering controls, and Sabine is in the copilot seat, also moving the steering controls. Two pilots cannot steer the ship at the same time.
The rebels' mission is to enter the atmosphere of Ibaar and drop food down to the surface. They encounter a blockade of 5 Imperial ships clustered closely together. The rebel ships push forward in a straight line right at the Imperial ships, leading to heavy losses. In a two-dimensional setting, like on the surface of a lake, this would make sense. It makes no sense in a 3D setting. All the rebels would need to do to circumvent the blockade is to enter the atmosphere at a different point, including the far side of the planet, away from the blockading ships.
Quarrie gives Hera grief about being a "combat pilot," yet he's the one who designed an advanced, heavily-armed fighter craft.