The NQ does not expire and does not need to be revalidated. However you will not be allowed to carry PAX at night if you have not done the following:
Lasors Section E13 paragraph E4.2
Within the previous 90 days you have made at least 1 take off and landing at night.
So basicaly if you do the above at least every 90 days there will be no restriction. However you do not have to do the above if you dont want to carry pax at night.
As far as FAR 61.57..that is an FAA regulation and does not apply to your JAA/CAA license