Not very. Take it from me, Egyptian hieroglyphs are hard to learn and hieratic (what almost everything not carved in stone was written in) is even harder. Almost all communication between Egyptians and foreigners was written in cuneiform, a writing system of strokes and impressions in clay, since it was more widely used in the Middle East and much more condusive to writing on clay tablets. As for language, I cannot think of a single instance where non-Egyptians living outside Egypt used the Egyptian language (currently don't have access to any research so can't be certain). I am not sure about the Old and Middle Kingdoms, but during the New Kingdom the lingua franca of the region was Akkadian, which was a Semitic language from Babylon. This can be observed in the Amarna Letters, which are tablets written in Akkadian cuneiform with correspondence between the court of the pharaoh Akhenaten and local officals in Canaan.