请问8老师夫父母有绿卡可以在国内最长呆多久?
-Depends on whether it is occasional or very often. It is occasional, they may stay there for less than one year (had better less than 6 months). If they travel to China very often, then they may have trouble. So, it is hard to say. Please remember, the green card is for them to live in US permanently, not for thme to use it as border-crossing card.
另外,如果申请re-entry permit, 是否需要在出发日子至少60前提交申请?-Not have to.
等打完指纹就可以回国吗?-Yes.等办完了, 我再寄回去, 可以吗-Yes.