A licence being ICAO compliant doesn't necessarily mean that other countries will accept it, at least not easily. What I'm saying is, don't bank on it! But it is true that the process between most countries will work. if you got your FAA then went to EASA, you would get a reduction in study time but would still have to take the 14 exams. if you went to Canada, you can get an equivalent licence for just a small exam. Just depends where you go.
Quadrant is just a different way of accepting the answer. It doesn't affect the questions otherwise, except maybe you do need to know the answer
