2 dan pro is a much stronger strength than 2 dan amateur. The difference between a 2 dan pro and a 9 dan pro is usually just one stone handicap whereas the difference between a 2 dan amateur and a 9 dan amateur would be around 7 stones.

You need to keep in mind that professional Dan levels aren't purely based on ELO or some other objective measure.

You'll find lots of Korean pros who got awarded their 1p for going abroad and teaching. 8p and 9p in Japan, in my recollection, are reserved for those winning one of the major tournaments and defending a title there.