And just to add more confirmation, your parents will probably get a World Club Lounge pass upon check-in (even on award tickets) and can start using the Lounge in DTW (but not in EWR even though they are booked in domestic First).
I don't believe NW has their own World Club Lounge in PEK so be sure your parents ask for who they share a lounge with and get a pass.
Their connection time in NRT probably is a little short to use the Lounge in NRT but they might want to as the boarding area in NRT is such a mass mess of bodies. However, the tiny elevator to get up to the lounge is such a hassle and going up the stairs is not that fun
CS
[This message has been edited by ChinaShark (edited 07-11-2001).]