Yes the 4g inverted does sound extreme and well beyond the way we flew the Hawk... although we did teach and fly 4g for all low level turns - something we don’t do on the frontline.
The low-level cruise speed on the Goshawk seems a bit odd too. We cruise at 420kts at low level in the Hawk, keeping more energy and performance in hand. As well-matched 1v1 Hawk fights frequently end up with both players at base height / opposite sides at 300kts or so we are attuned to the rubbish performance at such low speeds. The comments suggest the 360+-30kts cruise is to mitigate bird strikes, but thanks to one regular poster on this forum the front screen was considerably strengthened on all Hawk derivatives many years ago. Flying in the 300kts range in rising terrain is not a great place to be. If you are trying to pull 4g at that speed the AoA will climb rather rapidly and the energy will drain away - a very poor place to be in a Hawk / Goshawk.